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View Full Version : Future Fuels for GA


Cubdriver
04-03-2009, 05:10 AM
In my thread "Future 737" I post newsclips on biofuel and alternative fuel development for transport category aircraft, airliners and turboprops. The thread also includes developments in high efficiency turbines, since the two go together.

But there is another front that needs to be covered: the development, testing, and certification of biofuels, alternative fuels, and new engines for General Aviation (GA) aircraft. This thread will move a little slow because there is less money in the field. But it is topic that will have a definite impact on flight school aircraft, light commercial aircraft, and all other aircraft in the category. Diesel and turbo-diesel engines will be covered here as well if it relates.

From today's AOPA EPilot-

Another step taken in search for alternate fuel


Teledyne Continental Motors and Hawker Beechcraft have joined forces to move the search ahead for an alternative to 100LL by testing a 94-octane “no lead” aviation gasoline in flight. A Beechcraft G36 (Garmin G1000-equipped) Bonanza flew several flights, the longest to date lasting one hour, with 94 unleaded fuel that was specially blended for aviation purposes. Although this was heralded by Continental President Rhett Ross as another of his company’s impressive aviation firsts, there may still be a long road ahead in the alternative fuel search. Read more and watch the Bonanza’s first flight with unleaded fuel >> (http://www.aopa.org/aircraft/articles/2009/090401altfuel.html?WT.mc_id=090403epilot&WT.mc_sect=tts)

From AOPA Pilot Dec. 2008-

FAA Tech Center evaluates future fuels (http://www.aopa.org/aircraft/articles/2008/081223fuels.html?WT.mc_id=&wtmcid;&WT.mc_sect=gan)

By AOPA ePublishing staff


When it comes to the future of aviation fuels, there’s one place to turn for definitive analysis—the FAA’s Alternative Aviation Fuel and Engine Test Facility, part of the WJH Technical Center, located in New Jersey.
Engineers at the facility are dedicated to working with industry to evaluate fuel options, including possible successors to 100LL avgas.
“I think our facility has been a leader in the area of research to help find a solution—a safe, environmentally friendly solution—to what we all know will eventually go away,” said Dave Atwood, an engineer at the facility who works with a team of seven people to test possible alternatives for leaded avgas.
Not only do they analyze potential fuels developed by universities and oil companies, they also provide guidance that can be used to help develop new fuels to test.

From AOPA Pilot Nov. 2008-

Goodbye Big Blue? The future of avgas (http://www.aopa.org/members/files/pilot/2008/goodbye0811.html)

by Dave Hirschman


Pilots have been forewarned of the imminent demise of leaded avgas for many, many years and the blue fuel is still plentiful. So it’s easy to dismiss talk of its looming disappearance now as alarmist rhetoric.
But regulatory and market forces are combining in powerful new ways that may someday force 100LL into extinction. And general aviation companies, including engine and airframe manufacturers, electronics, and petroleum firms, are taking steps to prepare new products designed to allow piston airplanes to keep flying into the future.
“After 20-plus years of research, no silver bullet replacement fuel has yet been found to satisfy the needs of the entire general aviation fleet,” said Rob Hackman, AOPA’s senior director of regulatory affairs. “So a second option that appears more likely would include some sort of engine modification for a portion of the fleet in addition to an unleaded fuel. It remains to be seen whether a bolt-on, FAA-certified, aftermarket solution will become available at a realistic price. AOPA members are the end user, and we’re going to continue to make sure their interests are protected. Whatever the industry agrees upon as a replacement to 100LL, it’s got to be safe and legal for the entire fleet to use and allow as much time as needed for the industry to transition.”


rickair7777
04-03-2009, 05:23 AM
Could LL engines be modified with new valves and seats and run on unleaded with an octane booster? It is RELATIVELY cheap to pull heads on those things.

Ewfflyer
04-03-2009, 09:03 AM
I do like the work Cont. Eng's are doing, hopefully something comes of it. I'm still concerned as mentioned above with Valves and detonation issues, but they've put 4-5 flights on the plane so far and it hasn't fallen out of the sky yet!


ryan1234
04-03-2009, 12:00 PM
wonder how they'll handle the STCs for everyone...
also... I wonder if a switch to a new, slightly cheaper fuel will give the ammo for a tax on aviation use fuel possibly bringing the price up to par with 100LL?

Cubdriver
04-03-2009, 12:37 PM
Could LL engines be modified with new valves and seats and run on unleaded with an octane booster? It is RELATIVELY cheap to pull heads on those things.

Rick-

In a word, no they can't. There is no drop-in octane booster additive that does everything TEL (tetra-ethyl-lead) in 100LL does. In addition, the piston aircraft engine industry does not have the kind of money and resources to launch an attempt to develop and certify drop-in cylinder head replacements for the existing piston engine fleet. This was possible for the auto-industry in the 1970s. The business case the automobile industry enjoys for this is a very different scenario.

1) The TEL (tetra-ethyl-lead) additive in 100LL Avgas is put there to boost the octane of the fuel. Airplane piston engines need a higher octane rating fuel because they run high-compression engines. High compression engines operate at a higher percentage of their total operating speed range. They need the higher octane and compression to permit higher mass flow rates used with supercharged and turbocharged engines, and to avoid the potential damage from detonation. Cars do not have these features although some of them are used in racing cars. In a word, aviation engines are high performance engines and they need high compression fuel.

2) High octane fuel gives less detonation. Less detonation gives better power extraction from the fuel, better burn performance, less wasted energy, and less damage and stress to the engine. Aircraft engines are safety critical engines. They need the extra reliability afforded by high compression, low detonation engines.

3) You can't run high octane engines on low octane fuels or damage will result. Some low-compression aircraft engines can, with a host of caveats and considerations, obtain an STC to operate with auto gasoline or mogas. As we know, the airplanes designed for use with 100 and 100LL tend to have very long service lives. They do not phase themselves out the way cars phase themselves out over a decade or so. You need to have an octane booster to replace TEL (100LL) if you want these engines to survive for multiple decades. To date, no such replacement has been invented. A large percentage of the existing fleet can use 91/96 unleaded gasoline, perhaps even 70%, but there is a large number of airplanes not served by this substitute fuel. Those engines are true high performance engines that need the high performance characteristics associated with the TEL additive.

4) For decades TEL was used to boost the octane of fuels used in cars and trucks across the modern world and allowed the production of very strong engines. High compression engines made before the ban on leaded automotive fuels are still prized by performance car enthusiasts for the extra horsepower they put out. In 1973 the toxic effects of TEL were shown to be the case, and as a result of this and the fact that lead interferes with the action of catalytic converters used for emission reduction the EPA won regulation against the use of leaded automotive fuels. That's a good thing supposedly because lead in the atmosphere is a very harmful, a topic for other discussion. Engines went to lower compression ratios at an expense in the millions in terms of research and redesign for engines for cars. Avgas remained exempt from the law because developing new cylinder heads for small aircraft engines would have cost more than any of the major engine manufacturers could bear. There are high design, manufacturing, and certification costs associated with aircraft engines and they tend to change very slowly in comparison with automobile engines. It is a smaller industry and it cannot afford to accomodate the rapid changes imposed on the auto industry. At this time, a drop-in replacement for 100LL fuel is what is really needed.

5) TEL in 100LL also cools valve seats and prevents corrosion in the engine. Carmakers had to come up with tougher valves and valve seats that could withstand the higher temps of detonating fuels and the corrosive effects of unburned mixtures. This could be done for aviation engines as you suggest, but it's really not the main issue. High compression ratio-compatible fuel is what is needed at this point.

6) There is a lot of hope in this regard. Funding for alternatives to 100LL is ongoing and is fairly well funded. Some notable programs are the Swift Fuel invention from Purdue University, and the FAA research on the subject being conducted at their New Jersey facility.

Here's a little bit of sleep-inducing material on the subject.

AOPA on leaded gas (http://www.aopa.org/members/files/pilot/2002/lead0205.html)
AOPA on 100LL (http://www.aopa.org/whatsnew/regulatory/regunlead.html)
Wiki on aircraft engines (http://en.wikipedia.org/wiki/Aircraft_engine)
Wiki on avgas (http://en.wikipedia.org/wiki/100LL)
Wiki on gasoline (http://en.wikipedia.org/wiki/Leaded_gasoline#Lead)
Wiki on octane (http://en.wikipedia.org/wiki/Octane_rating)

Cubdriver
04-10-2009, 06:36 PM
Future Power Under the Microscope

Thomas A. Horne (AOPA)

A panel discussion at AERO focused on the opportunities and challenges of the proposed alternative propulsion systems of the future. The views were as enlightening as they were divergent. Mike Kraft of Lycoming engines emphasized that traditional spark-ignition engines remain the most efficient at transforming avgas into power. Lycoming has been conducting tests with biomass fuels, but so far Lycoming has concluded that it will be difficult to anticipate the exact nature of future general aviation fuels. “We’re anticipating the software and strategies that we may have to use,” Kraft said, adding, “If we go to a fuel that doesn’t have the current energy properties of avgas, traditional engines won’t behave the same. So airframe manufacturers, engine manufacturers, and fuel suppliers must all cooperate in developing a future fuel.”



German firm debuts hybrid LSA engine

from AOPA Online (http://www.aopa.org/aircraft/articles/2009/090403futurepower.html?WT.mc_id=090410epilot&WT.mc_sect=gan)/ AvWeb (4/5)

German manufacturer Flight Design has unveiled a new hybrid engine for its CT line of light sport aircraft. The new design uses an electric engine for takeoff and climb, before the traditional, 130 hp gasoline engine takes over for cruising. Flight Design says the hybrid feature increases safety, since the electric engine can take over during an emergency, increasing the aircraft's glide time for a safe landing.

mshunter
05-02-2009, 09:24 PM
Very well writen, but I would not consider 8.5 to 1 compression ratios (i.e. IO-550) to be high compression. The main reason why we use leaded gas in aviation is because of it's "cushoining" effects and cooling effects. Being a former Auto tech, the majority of engines produced today are 9.0 to 1 and higher. Motorcycle engine are 12.5to1 and higher. They all can run on 91 octane. The auto makers have figured out how to make power with unleaded fuels, and higher compressions mostly with valve timing. If you can get the valve timing events right, you can make just as much power on lower octane ratings, with higher compressions.

Also, aircolled engines tend to operate at higher tempatures than liquid cooled engines. Have you ever heard an auto "diesel" when it shuts down? This is basically due to the fact that either the timing was to high causing excessie heat in the cumbustion chamber, carbon on top of the piston and in the cyl. heads cumbustion chamber being red hot and continueing cumbustion, or the temp of the engine being to high, causing again, the cumbustion chamber to be to hot and not stoping the ignition cycle.

On to the catalic convertor issue. Don't run leaded gas in anything with a cat convertor. Like you have stated, it will ruin the convertors efficency, but the EPA is misguided. Remember what the lead does to the valves and seats? It cools them. So it does the same thing to the convertor. A cool convertor works less efficently than a hot one. But what it also does is plug it up. A pluged convertor simply won't let the exhaust flow.

Now, my opnion on a need for alternative aviation fuel. It simply is not needed. The lead 100LL fuel accounts for in the atmosphere is less than 1%. But, if they want to make it work, it can be done without completely re-enginering aviation engines. So what happened to all the auto's with the improper valves and valve seats. Some of them are still on the road. What about 100 (green fuel). It contains no lead, and we can still run it in our airplanes with no ill affects. It's a simple matter of octane.

What exactly is the affect of higher octane? In it's simplest terms, the higher the octane, the slower the burn. The higher the cyl. pressure (i.e. compression ratio), the faster the burn. So a compression ratio of 10to1 will require a higher octane, or if turbocharged (increased cyl. pressure and heat) will reauire a higher octane for a given compression ratio (8to1 non-turbo=87 octane, 8to1 turbo=93octane). The more pressure an engine makes with the cumbustion process, the more heat it makes, which we have already established will lead to detonation. If we increase the octane rating of the fuel (i.e. go to 130 octane), we should not need the lead in the fuel any longer. Take the lead out, the fuel gets less expensive. Increase the octane, it gets more expensive. Back to square one with price now.

In my opnion, there is too much thought going into our fuel, when the fix is rather simple. Increase the octane that is availible(which will cool things down), take the lead out, and the problem solved.

It's late, and I have much more to type, but it's time to stare at the backside of my eyelids.

jonnyjetprop
05-10-2009, 05:31 AM
There is on going research into electricon ignition systems that would allow big bore engines to run on a special aviation fuel. It's unleaded gas that I think is around 93-94 octane. The issue is that the ignition system would detect knocking and adjust the timing.

On a second note, it's problematic to run a low compression engine on auto gas. You can't use fuels that have ethanol mixed in it.

mshunter
05-10-2009, 01:06 PM
There is on going research into electricon ignition systems that would allow big bore engines to run on a special aviation fuel. It's unleaded gas that I think is around 93-94 octane. The issue is that the ignition system would detect knocking and adjust the timing.

On a second note, it's problematic to run a low compression engine on auto gas. You can't use fuels that have ethanol mixed in it.


On the contrary. Ethanol is used as a detonation buffer. It takes much more ethanol to make the same power as a petrol based fuel, but it also generates significantly less heat, which is one reason why the lead is added to av-gas. I for one, am against an ethanol based fuel, because it costs energy to make it (more energy goes into making than it yields).

The reason why we don't add ethanol to av-gas is because of the what the engine cases are made of. There is a measurable amount of magnesium in the case (block) of opposed engines to save weight. Ethanol corrodes magnesium, and the unburnt fuel that makes it way past the rings would corrode the case over time.

We can do it without completely overhauling the system. If we increase the octane (which will generate less heat) and eliminate the lead, in theory, problem solved.

Cubdriver
05-20-2009, 10:55 AM
Very well writen, but I would not consider 8.5 to 1 compression ratios (i.e. IO-550) to be high compression these days.
It seems like a contradiction that aircraft engines have lower compression ratios than the average car. The numbers may differ, but so do the operation regimes. Aircraft engines operate at a higher percentage of their total operating range. Airplane at cruise= 85% or more of total RPM range, versus a car cruising down the highway may be at about 35%.The main reason why we use leaded gas in aviation is because of it's "cushoining" effects and cooling effects. Agreed.
Being a former Auto tech, the majority of engines produced today are 9.0 to 1 and higher. Motorcycle engine are 12.5to1 and higher. They all can run on 91 octane. The auto makers have figured out how to make power with unleaded fuels… Same story here- these engines do not operate at a very high percent of their respective RPM ranges. In addition, the higher compressions you see today are the result of lots of R&D. Back in 1971 when automakers backed off compressions for the first time, values around 8-9 were common. Only later was it possible to bump it back up as engines were redesigned, something which was very expensive to do.
…and higher compressions mostly with valve timing. If you can get the valve timing events right, you can make just as much power on lower octane ratings, with higher compressions.Agreed- and this is the operating principle behind PRISM (pressure-reactive intelligent spark management system) from GAMI of Ada, Oklahoma. It is not in use due to high certification costs.
Also, aircolled engines tend to operate at higher tempatures than liquid cooled engines. Agreed in general, especially for cylinder head temps. I will have to look into the flame temps and exhaust gas temps but I think they are similar for the two engines. Cooler cylinder walls can affect the burn quality for the better. A Continental O-520 may run at about 1400F EGT and 400F cylinder wall temps at full thrust. The cylinder wall temps are a lot more than in a water cooled engine. I do not think the flame temps are very different however. Higher cylinder walls would seem to indicate higher octane fuels are needed, because there is more available activation energy (heat). Have you ever heard an auto "diesel" when it shuts down? This is basically due to the fact that either the timing was to high causing excessie heat in the cumbustion chamber, carbon on top of the piston and in the cyl. heads cumbustion chamber being red hot and continueing cumbustion, or the temp of the engine being to high, causing again, the cumbustion chamber to be to hot and not stoping the ignition cycle. Yeah I have heard of it. Aviation engines will do it a little bit too even with low lead gas.
On to the catalic convertor issue. Don't run leaded gas in anything with a cat convertor. Like you have stated, it will ruin the convertors efficency, but the EPA is misguided. Remember what the lead does to the valves and seats? It cools them. So it does the same thing to the convertor. A cool convertor works less efficently than a hot one. But what it also does is plug it up. A pluged convertor simply won't let the exhaust flow. Ok. I am not sure about the EPA being misguided... but it doesn’t matter to aviation.
Now, my opnion on a need for alternative aviation fuel. It simply is not needed. The lead 100LL fuel accounts for in the atmosphere is less than 1%. EPA agrees as well, hence the exemption we have for aviation using leaded fuels past the 1996 deadline for cars and trucks. But it’s not just about the EPA. Leaded gas is only made by one small company and they could go out of business at any time. Or the EPA could rescind our exemption on leaded avgas. We need to get another fuel ready. But, if they want to make it work, it can be done without completely re-enginering aviation engines. Well, 70% of them do not need re-engineering to work to run on lower octanes, but the other 30% do and they are the root of the problem. And the cost of re-engineering them would be very high. Who is going to pay for it? They do not sell enough to spread the cost out and they are already very expensive engines as they are.So what happened to all the auto's with the improper valves and valve seats. Some of them are still on the road. And most of them are not. So you are saying there was never a need for re-engineering auto engines to run on no-lead gasoline? You are not correct. There was, and it was done at a cost of many millions by US automakers in the 1970s.
What about 100 (green fuel). It contains no lead, and we can still run it in our airplanes with no ill affects. It's a simple matter of octane.No- it has even more lead. Avgas 100 Green has about .85 grams per liter lead, while Avgas 100LL Blue has about .56 grams per liter of lead. What exactly is the affect of higher octane? In it's simplest terms, the higher the octane, the slower the burn. The higher the cyl. pressure (i.e. compression ratio), the faster the burn. So a compression ratio of 10to1 will require a higher octane, or if turbocharged (increased cyl. pressure and heat) will reauire a higher octane for a given compression ratio (8to1 non-turbo=87 octane, 8to1 turbo=93octane). The more pressure an engine makes with the cumbustion process, the more heat it makes, which we have already established will lead to detonation. Agreed as long as we are speaking in generalities. It’s more about the evenness of the flamefront during the burn cycle but close enough. If we increase the octane rating of the fuel (i.e. go to 130 octane), we should not need the lead in the fuel any longer. Actually octane is not the problem. There are many fuel additives that can provide high enough octane numbers, ethanol for example. But all of them have problems such as cooling properties, toxicity to the environment, cost per gallon, low energy density content, and so on. If it were simple problem to develop a replacement for TEL (lead) a major petroleum manufacturer would have done it decades ago.
Take the lead out, the fuel gets less expensive. Increase the octane, it gets more expensive. Back to square one with price now. I am not sure what your point is here?
In my opnion, there is too much thought going into our fuel, when the fix is rather simple. Increase the octane that is availible(which will cool things down), take the lead out, and the problem solved....It's late, and I have much more to type, but it's time to stare at the backside of my eyelids.Taking the lead out will destroy 30% of the piston engine aviation fleet, which may seem to be a good solution when you're at the end of a 4 day trip. :) This exact strategy used by Detroit in the 1970s to dispose of most of the existing cars that ran on leaded gas in previous ages. But do you as the owner of a brand new $50,000 Lycoming TIO540 airplane want the engine destroyed in say, five or ten years while the rest of the airplane is perfectly fine? Of course not, and this is why there is a big fuss being made over finding a "drop in" replacement for leaded avgas.

Cubdriver
06-02-2009, 12:32 PM
I had the pleasure of giving Ms. McMillan a glider tow the other day...

Planemakers challenged to find unleaded fuel option
BY MOLLY MCMILLIN, The Wichita Eagle (http://www.kansas.com/business/story/833098.html)

The elimination of lead from automotive fuel has long been hailed as a top environmental achievement. But finding a replacement for the leaded aviation fuel that powers tens of thousands of piston engine aircraft flying in the United States today has proven to be much more difficult. Eventually, the Environmental Protection Agency will phase out its use. And economic factors could affect its cost and continued availability. Identifying the right fuel and putting in a plan to transition to it is vital, said Walter Desrosier, vice president of engineering and maintenance at the General Aviation Manufacturers Association, an industry trade group. It's necessary to "ensure the viability and health of the general aviation industry," he said. The industry cut the amount of lead additive in aviation fuel in half during the 1980s -- resulting in the 100 octane "low lead" aviation gasoline in use today -- in response to health concerns about lead. That's the minimum octane necessary to ensure safe flight of the existing fleet of general aviation aircraft, GAMA said. But finding an acceptable fuel without lead is taking time. "We did not find a fuel that we can simply replace 100 low lead and it would have the same level of performance and the same level of operation for the entire fleet of general aviation aircraft," Desrosier said. A replacement must ensure the aircraft would operate safely, be environmentally friendly, economically feasible and have the ability to be widely distributed to airports and fixed-base operators, the trade group said."We've never had to go backwards and approve an existing engine and an existing airplane to a new fuel," Desrosier said.

Only one supplier left
The world has moved away from lead additives in fuels, and demand has plummeted. With less demand, there's only one main supplier of the lead additive used in avgas in the world. That brings with it the risk of rising costs or interruption of supply, Desrosier said.The supplier, Innospec in the United Kingdom, has assured the industry it will continue to produce the additive and make it available. Still, there's risk, Desrosier said. "If something happens in the transportation... suddenly there's a stop in supply and 100 low lead avgas may not be available," he said. That would have a detrimental economic impact to the U.S. Piston-powered aircraft engines, high-performance engines in particular, have been built for use of high-octane leaded fuel.The lead boosts the fuel's octane rating, and that helps prevent destructive detonation that can occur with the high-performance engines. "If you don't have 100 octane fuel -- leaded or unleaded -- those aircraft will be grounded without significant investment," said Michael Kraft, vice president of research and development and engineering at Lycoming, an engine manufacturer.It's a big issue for Wichita planemakers. "We're trying to find an alternative that will work with the planes that are out there in the fleet," said Stan O'Brien, Hawker Beechcraft's project engineer for piston engine aircraft. "It makes it a difficult challenge." Performance levels on aircraft must be tested. "Can you imagine if you just bought a new Bonanza last year and we say, 'Oh, by the way, here's your (new, lower) performance levels,' " said Hawker Beechcraft vice president of product development and engineering Ed Petkus. "You wouldn't have happy customers."

Unleaded options
Two unleaded fuels are being evaluated for their potential. One is a petroleum-based fuel similar to avgas, but without the lead. Most of the planes flying would be able to use it and have the ability to make a transition to it relatively easily, Desrosier said.But because the octane is lower, high-performance aircraft would need physical modifications, Desrosier said.Only 30 percent of the fleet using avgas are high-performance planes, but they consume 70 percent of the fuel. They're the planes most likely to be used in commercial businesses. They would feel the biggest impact."We need to understand the affect to the fleet and what modifications would be available at what cost," Desrosier said. A second fuel undergoing testing is a synthetic bio-based fuel produced by Swift Enterprises in Indiana. It's high-octane and unleaded. So far, it's performed well and seems promising.Hawker Beechcraft's Bonanza G36 was the first to fly on Swift's fuel, the company said. The Swift fuel must still be tested and validated to ensure its compatibility with an aircraft's structures -- the aluminum, hoses, seals, fuel bladders and fuel systems, Desrosier said. And its distribution and the ability to produce it must be determined at the cost, quantity and quality needed. The fuel is heavier, or more dense, than avgas. But it also has a higher energy content, Desrosier said. Lycoming is not endorsing a particular company but sees promise in a synthesized high-octane fuel, Kraft said. Engine makers are testing unleaded fuel. Lycoming, for example, is making sure any new engine is capable of running on lower-octane unleaded fuel, Kraft said.Last year, it introduced an engine that can use whatever the fuel of the future will be."You have to be very much in tune with the fuel to correctly design the engine," Kraft said. "That's really driving all of our (research and development)."

rickair7777
06-02-2009, 04:12 PM
At least Lycoming is making flexible engines now, that's a start.

Cubdriver
06-03-2009, 06:04 AM
They are working on an ASTM-certified automotive gasoline approval program for some (many?) of their existing 4 cylinder models, but this has nothing to do with new products. They are also working on an engine with advanced spark and fuel control called the iE2. This engine might be the answer to flex fuel purposes, but as of now it only exists in a six-cylinder turbo configuration. I am not aware of a flex fuel engine, per se. I believe they consider it too expensive to develop one. Even the iE2 is largely derivative from the IO-540. No doubt a clean-sheet flex-fuel engine could be made by someone, but as always the problem is paying for it.

iE2, etc. (http://www.aviationtoday.com/am/categories/bga/Whats-on-the-Horizon-at-Lycoming-Engines_30005.html)

rickair7777
06-04-2009, 06:25 AM
They are working on an ASTM-certified automotive gasoline approval program for some (many?) of their existing 4 cylinder models, but this has nothing to do with new products. They are also working on an engine with advanced spark and fuel control called the iE2. This engine might be the answer to flex fuel purposes, but as of now it only exists in a six-cylinder turbo configuration. I am not aware of a flex fuel engine, per se. I believe they consider it too expensive to develop one. Even the iE2 is largely derivative from the IO-540. No doubt a clean-sheet flex-fuel engine could be made by someone, but as always the problem is paying for it.

iE2, etc. (http://www.aviationtoday.com/am/categories/bga/Whats-on-the-Horizon-at-Lycoming-Engines_30005.html)

I understood that they were working, not necessarily on flex-fuel engines, but on engines which would be readily adaptable to different fuels without major design mods.

Cubdriver
06-26-2009, 05:41 AM
AOPA works on aviation fuel specs
By AOPA ePublishing Staff- June 24, 2009

As the industry explores possibilities for new fuels for general aviation aircraft, AOPA continues to be actively involved in fuel issues. The association participated in meetings this week with ASTM International, the organization that sets consensus standards for fuel used in FAA type-certificated aircraft. The meetings, held in Norfolk, Va., included discussions on leaded, unleaded, and diesel fuel specifications. As the industry researches fuel options outside of 100LL, the role of ASTM in the fuel specification process will remain important. “In the search for alternative fuel types, it is critical that any proposed alternative is economical and operationally equivalent to the fuels used today and that it can be used without major changes to the engines in use today,” said Leisha Bell, AOPA manager of regulatory affairs. “AOPA is involved every step of the way, from the early stages of research through production.” A newly established ASTM task force met in Norfolk to begin developing a fuel specification for diesel used in piston engines. The importance of adhering to fuel specifications was highlighted last year when ExxonMobil announced that it “does not support or endorse the supply of jet fuel for aircraft (http://www.aopa.org/aircraft/articles/2008/081125exxon.html?WT.mc_id=&wtmcid;&WT.mc_sect=gan) powered by diesel engines,” citing differences between the specifications for jet fuels and the requirements of aviation diesel engines. Jet fuel is not tested for the conditions and operation of a diesel engine. The task force is designed to address these technical concerns.
ASTM (originally known as the American Society for Testing and Materials) is one of the largest voluntary standards development organizations in the world. AOPA is a voting member of the petroleum standards development group of ASTM and works to ensure that the organization includes standards for all current and future aviation fuels.

Cubdriver
07-06-2009, 01:08 PM
Plant Power; What's the answer to avgas?

By Dave Hirschman. The original claims describing a bio-fuel replacement for avgas sounded too good to be true.Swift Enterprises, a small start-up firm in Indiana, announced last year that it had developed an unleaded, domestically produced, higher-octane aviation fuel that could be manufactured and produced at a far lower cost than avgas. It promised its bio-fuel would reduce emissions 20 percent and increase aircraft range up to 15 percent.

Laboratory tests by the FAA confirm that Swift’s avgas replacement will work in current piston aircraft engines, even the high-compression, turbocharged varieties that are particularly susceptible to detonation. (Teledyne Continental Motors has begun flight tests using Swift fuel.) The bio-fuel burns cleanly, has acceptable vapor pressures, and even offers some range and performance advantages over traditional avgas. So far Swift has only produced its product in tiny batches. And the unit costs for making it that way are extraordinarily high.

U.S. refiners currently sell about 250 million gallons of leaded avgas a year. That may sound like a lot, but it’s far less than a day’s production of unleaded auto fuel. The world’s aviation emissions—including airlines and military jets—account for about 3 percent of all carbon-dioxide emissions, and general aviation is a tiny fraction of that amount. But avgas is one of the few fuels that still contain lead, and a combination of new regulations, environmental considerations, and economics may soon make leaded fuels untenable.

Swift plans to use switchgrass as its fuel source. An abundant, fast-growing plant that used to cover much of the American heartland before corn, soy, wheat, and other crops took over, switchgrass has a higher energy output than food crops, and using switchgrass in bulk won’t drive up food prices. Swift is building a manufacturing facility near Purdue University Airport in Indiana where company officials hope to prove the merits of high-volume fuel production.

Since Swift fuel is unleaded, it can travel in the same delivery pipelines refiners use to deliver auto gas. Avgas must be segregated from other petroleum products throughout the production and delivery process and stored in separate containers. Trucks, rail cars, and vehicles that carry leaded avgas can’t be used for unleaded fuels. Swift officials say they expect some cost savings based on its ability to use the existing transportation infrastructure for other unleaded fuels. FAA certification of Swift fuel, or any other bio-fuel, is likely to take several years at least. While Swift pursues FAA approval, it’s also selling its specialized fuel to car, motorcycle, and even air racers willing to pay a premium for the added performance they say it brings.

Diesel aircraft engines got a black eye last year when German manufacturer Thielert sought bankruptcy protection after the founder was accused of financial misdeeds. The company’s troubles dealt a serious blow to Diamond Aircraft and other aircraft manufacturers that depended on Thielert for a steady supply of engines and parts, as well as owners of aircraft with Thielert engines. Cessna had already announced plans to manufacture Thielert-powered 172 Skyhawks for the world market when Thielert imploded...

Note: See the complete article in this month's AOPA Pilot; subscription req'd.

Cubdriver
07-28-2009, 11:38 AM
Continental president gets the lead out en route to AirVenture
from AOPA Online's (http://www.aopa.org/oshkosh/oshkosh09/articles/090727nolead.html?WT.mc_id=090728epilotspecialcent ral&WT.mc_sect=fc)
Thomas B. Haines

(7/27/09) Teledyne Continental Motors (http://www.genuinecontinental.aero/) President Rhett Ross seems single-handedly determined to showcase how committed his company is to getting the lead out of avgas. As a demonstration of that commitment, Ross flew a turbocharged Cirrus SR22 from the company headquarters in Mobile, Ala., to EAA AirVenture in Oshkosh, Wis., at FL240 burning only UL94 avgas. UL94 is basically 100LL avgas without the lead component. With ASTM actively working the certification of UL94, TCM has shifted from testing the fuel to preparing its engines for its eventual introduction. Ross claims that bymid-2010, TCM will have equipped its entire product line of engines to run on unleaded fuel. Company pilot and engineer Keith Chatten accompanied Ross on the flight, the third extended flight for this standard production engine, which has now accumulated 20 hours on unleaded fuels. The flight followed an earlier test flight of 802 miles roundtrip from Mobile to Oshkosh conducted in two uninterrupted legs. “Today’s flight demonstrated that our standard factory turbo is ready for future fuels and has the fuel economy necessary to benefit our customers,” Ross said. “The engine was a joy to operate during this extended flight on UL94. With successful flights of both turbocharged and normally aspirated engines on unleaded fuels, we feel comfortable that TCM has solutions for the future and are now working to have them ready.”

Future fuels, airworthiness hot topics at AirVenture

(8/06/09) AOPA Staff- Talk about the future of leaded avgas, and you’ll have a captive audience of pilots. That was the case last week during an EAA-facilitated fuels panel discussion in Oshkosh, Wis. Representatives from the Environmental Protection Agency, General Aviation Manufacturers Association, FAA, and Coordinating Research Council spoke to a packed pavilion of 150 pilots. The panelists discussed the EPA’s recent call for information about the use of leaded avgas in general aviation aircraft. An EPA representative said that it is possible that an “endangerment” finding could be made. Pilots in the audience asked about a pending transition to an unleaded fuel and inquired about how quickly a transition might take place. In a meeting after the panel, AOPA met with other associations and industry representatives to discuss the move to unleaded fuel. AOPA and EAA are members of a coalition that GAMA formed to work on a plan for transitioning to an unleaded fuel. The groups will work with the EPA on a transition plan that impacts the industry as little as possible. AOPA also discussed another looming threat to the GA industry: maintaining an aging aircraft fleet. In meetings with EAA and the FAA’s Small Airplane Directorate, AOPA talked about educational outreach efforts to the pilot community. AOPA and the FAA had worked closely together to create a free online course, Aging Aircraft, that describes some best practices for caring for an older aircraft. “AOPA and EAA are able to better penetrate the pilot population with educational messages,” said Leisha Bell, AOPA director of aircraft and environmental issues. “These meetings with the FAA will help both of our organizations reach pilots with pertinent information they need to know to keep their aircraft airworthy.” Future collaborative meetings among the groups are planned for AOPA Aviation Summit in Tampa, FL, Nov. 5 through 7.

Cubdriver
08-18-2009, 02:47 PM
Grass for Gas: Flying a Real, Renewable Fuel (http://www.aopa.org/members/files/pilot/2009/september/fuel0909.html?WT.mc_id=ebrief)

By Dave Hirschman, AOPA Online (8/19/09; subscription required). Catching the clear fluid being poured into my airplane’s fuel tank was disconcerting to say the least. We all know that 100LL is blue, of course. And instead of the familiar smell of leaded avgas, this stuff carried the odor of a dank locker room, or a musty basement. For more than five years, Swift Enterprises, a small start-up firm founded by Purdue University Professor John Rusek and largely staffed by grads, has been designing and producing its own form of renewable fuel meant as an unleaded replacement for 100LL. Independent laboratories including the FAA’s fuel and engine center have tested Swift fuel and determined it performs as well as—and, in some areas, better than—100LL, in a variety of piston aircraft engines. More detailed tests are planned. Teledyne Continental Motors and Hawker Beechcraft have performed flight tests using Swift fuel in an IO-550-equipped Bonanza, and General Aviation Modifications Inc. (GAMI) has performed extensive ground tests.

Now, I was at Purdue University Airport to meet with Swift officials and—perhaps more important—to fly home to Maryland on a tank of Swift’s sorghum-derived fuel. My airplane, a Van’s RV–3 licensed in the experimental category, is equipped with a stock 150-horsepower Lycoming O-320 with a fixed-pitch prop—a combination virtually identical to those found on ubiquitous Cessna, Piper, and Beech airplanes ranging from 172s to Super Cubs. Swift is about to enter an exhaustive data-gathering period in which it will collect thousands of hours of test data from many airplanes using its fuel in flight. But my 450-nm trip from Lafayette, Indiana, to Frederick, Maryland (with a planned stop in Mansfield, Ohio) would be the longest point-to-point flight to date on Swift’s fuel. “We’ll be following you on FlightAware,” said John Ziulkowski, a Swift officer, researcher, and pilot. “But call us when you land. We want to know every detail.” Engine start and runup were completely normal. There’s no special technique for starting an aircraft with the new fuel, and the pretakeoff procedures were the same as ever.

Acceleration on takeoff was as brisk as usual, and the rate of climb was a typically robust 1,500 fpm at 110 KIAS—even though the 20 gallons of Swift fuel added about 10 pounds compared to the six-pound-per-gallon weight of regular avgas. (Swift fuel weighs about 6.5 pounds per gallon.) The RV–3 has single-point EGT and CHT probes, and the EGT consistently read about 75 degrees F higher than normal in cruise, while the CHT was 25 degrees F lower than normal. Swift officials attribute the differences to their fuel’s higher octane rating (about 104), which causes Swift fuel to burn slower and later in the combustion process. Level at 7,500 feet in cruise (20 inches manifold pressure, 2,450 rpm, 65 degrees OAT), I enriched the mixture slightly more than usual to keep the EGT at 1,400 degrees F or below. The CHT was 325 degrees F, and fuel burn on the 90-minute flight averaged 8.5 gph. Swift fuel is designed to mix seamlessly with avgas, so I stopped about halfway home in Mansfield, Ohio, to blend the two. With slightly more avgas than Swift fuel in the 24-gallon tank, the hot start procedure was identical to avgas.

[Note: For the complete article including a movie clip, go to the web link on the title.]

Cubdriver
08-25-2009, 01:11 PM
A New, More CO2-Absorbent Algae Strain?

By Todd Woody (http://greeninc.blogs.nytimes.com/author/todd-woody/) of New York Times 8/25/09) Aurora Biofuels Aurora Biofuels says it has developed a more voracious CO2-gobbling strain of algae, which produces an oil that can be converted into biofuel. A California start-up, Aurora Biofuels (http://www.aurorabiofuels.com/), says it has cultivated algae that doubles production of biodiesel by absorbing more than twice as much carbon dioxide as conventional strains. According to Robert Walsh (http://www.aurorabiofuels.com/aurora-biofuels-management.php), the chief executive of the company, Aurora’s breakthrough was to develop algae mutations that can ingest carbon dioxide regardless of the intensity of sunlight. “Algae have a built-in mechanism to be effective at low light and as it gets brighter during the day their uptake of carbon dioxide levels off,” said Mr. Walsh. “We’ve been able to go in and alter strains by natural mutation to cause the algae to deal with light across the whole spectrum. The algae continue to uptake CO2 through brighter light and are more productive.” He said Aurora has built a pilot facility “between a 7-Eleven and the beach” near Melbourne, Fla., and that for the past several months the new algae strains have been producing a gallon of biodiesel a day in an Olympic pool-sized pond. An algae-derived substitute for gasoline is the great green hope of the nascent biofuels industry (http://topics.nytimes.com/top/news/business/energy-environment/biofuels/index.html). Aurora is one of dozens of start-ups vying to bring an algae-based product to market that will be competitive with petroleum but does not take farmland out of food production, an issue that has plagued the corn ethanol industry. But significant hurdles remain — including finding ways to profitably extract and process the oil from the algae. Like some of its competitors, Aurora will offer power plants and other carbon emitters the opportunity to sequester their emissions by feeding carbon dioxide into ponds to stimulate the growth of algae.

Christopher Benning (http://www.bch.msu.edu/faculty/benning.htm), a Michigan State University professor of biochemistry whose work involves algae, serves on Aurora’s scientific advisory board. He said the data Aurora has shown him confirms the company’s claims. “They’ve proven that their proprietary strain can increase carbon sequestration and the ability of algae to utilize CO2 and grow higher biomass,” said Mr. Benning, who is compensated for his work on the Aurora advisory board. Mr. Walsh said the challenge for Aurora is to commercialize its scientific advance. “We’ve proven we can do it at Olympic-pool size — can we do it at 50 acres? Can we maintain the costs at scale?” he said. The company plans to have a demonstration plant capable of producing 1,000 gallons of fuel a day in operation by the second quarter of 2010. A full-scale production facility is to follow in 2011. Aurora has raised $25 million from investors that include Oak Investment Partners, Noventi Ventures and Gabriel Venture Partners. Mr. Walsh said that financing will be sufficient to see Aurora through the construction of the demonstration plant.

Cubdriver
09-17-2009, 02:11 PM
Researcher: Military Qualifications Key To Alternative Fuel Race.

Flight International (http://mailview.custombriefings.com/mailview.aspx?m=2009091501aiaa&r=2974686-3d6d&l=00f-672&t=c) (9/14, Decker) published an interview with Ted Aulich, senior researcher at the Energy & Environment Research Center of North Dakota University. Flight International describes Aulich as being "on the frontlines in the search for alternatives to Avgas and petroleum." When asked about which alternative fuel he sees winning the "alternative race," Aulich replied, "My guess is the first entity to come forward with a fuel that meets military qualification criteria and is close to economically competitive with petroleum jet fuel is probably going to gain some early market advantages, because there's a lot of interest on the part of the military to get access to a renewable fuel."

Herb Flemmming
09-22-2009, 03:22 AM
Continental and Lycoming build **** they need to have there faces slapped. Toyota 4 banger would be a good option.

Cubdriver
09-22-2009, 05:26 AM
Continental and Lycoming build **** they need to have there faces slapped. Toyota 4 banger would be a good option.

Taking your comment seriously for the sake of discussion, car engines were designed for different design objectives. There are and were many variables to consider even before avgas became a hot topic. The basic design aspects of a Lyco or Continental horizontally-opposed engine were nailed down over 70 years ago perhaps, but it was an evolution based on aviation requirements through-and-through. Here's a pretty good wiki article on it. I would say form factor and RPM operating ranges are the main differences, but there are many things to consider.

Aircaft engines (wikipedia) (http://en.wikipedia.org/wiki/Aircraft_engine)

It's not a totally crazy idea however. There have been automobile engines retrofits to modern piston airplanes in a couple of cases, with limited success. The Theilert diesels Diamond used for a few years in the DiamondStar twin was a car engine.

Herb Flemmming
09-22-2009, 06:58 AM
Toyota 4 banger aluminum block etc all the weight reduction in mind and a reduction gear box, a reliable one like on the PT6.

I know a car engine doesn't sit all day at 2350 like a a/c engine does but im sure it could last way past a 2000 hour TBO.

Cubdriver
09-22-2009, 09:55 AM
The TBO figure for most Lycos and Cont's is a recommended figure and is not actually a mandated overhaul time. Many of these engines have not been overhauled for several multiples of their TBO times. I do not agree with it as a practice, just to point out that the engines themselves can go the distance.

If you assume a 30 miles per hour average speed for the average car engine, then it goes about 60,000 miles in 2,000 hours. If it lasts for say, 120,000 miles or 4,000 operating hours, this equals two TBO-periods for an aircraft engine of the same sort. The latter are often still found in service, with regular overhauls of course, after as many as 6 TBO cycles. I get this number by dividing a hypopthetical piston airplane with 12,000 hours on it by 2,000 hours. Lots of these airplanes exist and many have the original engines.

Herb Flemmming
09-22-2009, 10:45 AM
The TBO figure for most Lycos and Cont's is a recommended figure and is not actually a mandated overhaul time. Many of these engines have not been overhauled for several multiples of their TBO times. I do not agree with it as a practice, just to point out that the engines themselves can go the distance.

If you assume a 30 miles per hour average speed for the average car engine, then it goes about 60,000 miles in 2,000 hours. If it lasts for say, 120,000 miles or 4,000 operating hours, this equals two TBO-periods for an aircraft engine of the same sort. The latter are often still found in service, with regular overhauls of course, after as many as 6 TBO cycles. I get this number by dividing a hypopthetical piston airplane with 12,000 hours on it by 2,000 hours. Lots of these airplanes exist and many have the original engines.



If you consider a topend overhaul going the distance.

Cubdriver
12-09-2009, 11:03 AM
[Biofuel-capable South African] aircraft takes to sky


Barbara Cole 12/09/09, Daily News (http://www.dailynews.co.za/) The first all South African-designed and manufactured aircraft is to be launched in Durban, South Africa next year. "This will probably be the best, most advanced, general aviation aircraft of its class in the world. It is totally state-of-the-art," said Richard Schulz, managing director of Adept Airmotive, based at Virginia Airport, Durban North. "Our timing is brilliant and we have stolen a march on the Americans and the rest of the industry who have cut their research and development budgets because of the recession. "This takes design and manufacturing to a new level," said Schulz, who is eyeing the international market.

General aviation is one of the biggest sectors in South Africa and refers to fixed-wing, non-scheduled aircraft. The way in which existing conventional engines, which come from America, have been built has not changed in 40 years, apart from "some progress" with very light aircraft, Schulz explained. Now, all that is about to change. The four-seater fuselage of the all-South African plane is a SA Ravin 500, manufactured from the most advanced composite material, which is lighter, stiffer and stronger than that used in existing aircraft. The avionics - the instruments - in the cockpit are also the most technologically advanced. The airframe is manufactured in Pretoria and the avionics are produced in Cape Town. The "completely new generation" engine, which has been specially designed and developed to go in the Ravin, but can also be fitted to other fixed-wing planes and helicopters, has been produced by Adept Airmotive, although some of the machining was outsourced to companies in Cape Town and Pretoria. Schultz is hoping to consolidate every aspect of manufacture in Durban next year. He has been in discussions with Trade and Investment KZN about establishing an aviation industry in the province.

His company's engine, which is 60kg lighter than conventional engines, has the most modern internal combustion technology and advanced materials and processes. The 320-horsepower engine burns less fuel than existing engines, and it is environmentally friendly. It runs on any fuel (except diesel), lead-free fuel, ordinary vehicle fuel and bio-ethanol. The engine is liquid-cooled as opposed to air-cooled, making it more reliable and more fuel-efficient. And its fuel consumption in cruise mode is 37 liters per hour, compared with 55-60 liters an hour in existing planes. "No other aircraft in its class can fly 2,700 nautical miles (4,995km) without refueling," said Schultz.

Members of the company's design team, headed by Raymond Bakker, were named Best Inventors of the Year in 2008 in a global award for advanced computer-aided design (CAD). Schulz began working on the engine about 10 years ago. When he ran out of money, an equity investor, Andrew Schoeman, put R5-million into the project. Another R10,5m came from the Department of Science and Technology's Innovation Fund. Now he is looking for further investment funding to take the project into full commercial production. "There has been huge interest from people who want to put the engine into existing aircraft. And we have potential orders from all over the world." Each plane will sell for R2,5m, half the price of a comparable aircraft sourced from overseas, he said. "The potential is that we can manufacture 200 a year by 2015," said Schulz. The aircraft will be unveiled at Virginia Airport [in Durban] in March or April next year.

Cubdriver
12-18-2009, 04:33 AM
Swift Fuel prepares for flight tests

By Dave Hirschman (AOPA Online) Swift Enterprises has announced Dec. 14 that it will begin large-scale tests of its unleaded, renewable fuel that it hopes to offer as a drop-in replacement for avgas. The Indiana-based company uses biomass such as sorghum and switch grass to produce a high-octane fuel that it says could replace leaded avgas in piston-engine airplanes. The fuel has been tested in FAA and independent laboratories and flown in a few Experimental-category airplanes. The test program will be coordinated with the FAA, and an extensive series of flight tests, data gathering, and evaluations must be conducted before the fuel known as 100SF can be certified for broad use in the general aviation fleet. Swift officials said the tests will begin as soon as the company receives FAA approval, and the tests themselves are likely to last up to two years. Engine and airframe manufacturers with sophisticated data gathering equipment will perform the bulk of the flight tests. Unlike other unleaded fuels, 100SF has an octane rating as high as avgas. Swift Enterprises has built a pilot plant in West Lafayette, Ind., the company says can produce about 200 gallons of 100SF a day. Swift officials say 100SF will be “comparably priced, environmentally friendlier, and more fuel efficient” than avgas.

hindsight2020
12-19-2009, 09:01 PM
As far as the fuels, "Comparably priced" ain't good enough. We need to break the 100LL racket for good, for the sake of GA. I'm sick and tired of flying beat-out 70 y/o technology lycos and continentals because they don't want to allow competition come in and eat their lunches. So we gotta live with "affordable" 4 time overhauled, lead fouled contraption while paying horrible economies of scales premium on highly toxic gas the industry would be better off phasing out already.

I run 87 octane unleaded on my O-200 and it loves it. 100LL has about 4 times the lead content the engine was designed to manage, yet aviation "red" 87 ceased to exist eons ago, and I'm forced to keep the continental with the busted carb, manual mixture and expensive overhaul barriers. Even so, I have a full 50% cost reduction by running 87 unleaded versus 100LL and since the engine is of low compression, I'm not paying a premium for octane I'm not taking advantage of and extra lead I don't need in my engine anyways. What does industry do in reaction? Stifle efforts to make unleaded available to GA. No pumps at the airport and I gotta jump through hoops to find non-ethanol gas outside and once I do, I gotta cart it to the airplane as if I was stealing something. This works for me since a C-150 only holds 22.5 usable, but for high capacity airframes, yeah the pain of going through that hoop stifles momentum for the average owner (never mind part 135 you can't even use mogas per regulatory schemes).

Lyco and continental just don't want to let the gig up and for the sake of GA we need to break that cartel. In 2009 it is just completely artificial to have to accept TEL on our engines for some anachronistic 70year old design consideration to valve seating (which I've barely paid attention anymore on my O-200 as I run almost exclusively on unleaded). We should have been running on unleaded-designed engines a long time ago. Bio fuels and fancy alternatives is fine, knock yourself out, but we should make the use of automotive unleaded widespread. It's good to hear the guys in south africa are making progress to that end, engine wise.

I just flew a rotax equipped experimental today and I burned 4 gallons of 87 unleaded for 1.5 hours of cheap pure flying fun. No carb heat, no mixture control, no lead fouling, no $4.50/gal price of entry to do what I love. Only thing I need is to get 1970s era production numbers on unleaded engine technology and we can truly get the experimental category becoming market price setters and kill off these leaded gas dinosaurs for good.

rickair7777
12-20-2009, 01:29 PM
Comparably priced is just a starting point...you have to get there in order to have any hope of penetrating the market.

But the beauty of most of these alternatives is that they are renewable...once economy-of-scale drives the prices down they will stay there. There will be no underlying non-renewable commodity cost to spiral out of control (ie oil).

Most folks are looking at biomass based feed stock...totally renewable. If the demand goes up, you just grow more. The only possible cost variable might be some energy required to refine the stuff, but hopefully grid power will become less reliant on fossil fuels also.

Cubdriver
12-20-2009, 06:35 PM
The problem with piston singles since about 1975 is they are not scrapped out in high enough numbers to be replaced by modernized units like cars and trucks are. That Skycatcher sold in 2010 will still be tied down somewhere in the local airport world in 2050, perhaps with an owner hauling mogas through the fence at midnight to fuel it. There is no conspiracy, just insufficient numbers to flush the system of older airplanes.

A lot of the price of leaded avgas is in the heavy taxes, the tiny scale of production, and the fact it is not traded as a commodity. The cost of the lead content is a fairly minor factor. Switching the GA fleet over to no-lead engines will not change the price of avgas very much if at all. The only way to get a serious drop in the price of avgas is to do away with avgas altogether and go to mogas. That is not going to happen, but more power to those who have the biceps to haul it from the mini-mart.

The main motivation for biofuels is having something ready when the EPA finally says "no more lead", and when as Rick points out there is another huge dip in the production of oil. Cheap avgas isn't the only goal although it would be nice.

We presently have a bonus depreciation tax break to spur new airplane sales. See AOPA Bonus Depreciation article 1 (http://www.aopa.org/aircraft/articles/2009/090305taxincentive.html) and AOPA Bonus Depreciation article 2 (http://www.aopa.org/members/files/pilot/2009/august/taxsavings0908.html). The problem with this is it only applies to business aircraft and I think, aircraft costing over $200k; it does nothing to sell sport planes or remove any lead burners from the market. There needs to be a cash for clunkers offer extended to outdated piston airplanes added to the existing tax depreciation incentive. This would help get rid of the lead burners, stimulate sales of new aircraft, and stimulate R&D in one move. Bring in your Lyco 360 and go out with the no-lead version, or get a relatively inexpensive brand-new airplane.

aeromike49
12-20-2009, 07:04 PM
Replacement fuel for leaded avgas will have to accommodate the airframe which is more of a problem (and could be more costly) than the engine modifications. Who is going to pay for all the testing in each and every current airframe so as to be able to use an alternate fuel? Seems to me like a lot of planes will be useless/worthless without certified fuel to operate them? Imagine what alcohol will do to a "wet wing" after a few years ?

Cubdriver
02-16-2010, 11:15 AM
Revolutionary answer-GAMI formulates unleaded piston-engine aircraft fuel

Justin Lofton Staff Writer

Ada (http://www.adaeveningnews.com/local/local_story_046093130.html) — George Braly and Tim Roehl may have solved a problem that’s been plaguing the aircraft industry and the Environmental Protection Agency for years. Braly and Roehl, owners of General Aviation Modifications, Inc. at Ada Municipal Airport, say they have formulated an unleaded piston-engine-aircraft fuel that may revolutionize the industry because it produces the same octane rating as leaded fuel.“We have one of the finest test facilities in the country for being able to evaluate the octane performance of various fuels,” Roehl said.In November 2007, Friends of the Earth — an international network of environmental organizations — petitioned EPA in attempt to get "avgas," a high lead fuel regulated. Roehl said due to a court case with Friends of the Earth the EPA must finally force a removal of lead from avgas.“Having been familiar with a lot of the formulations that have been tried in the past, we decided to formulate our own fuel,” Roehl said. “After about a month of testing, we feel confident that we have, in fact, come up with a fully 100 Motor Octane Number unleaded avgas fuel that meets essentially all of the requirements that avgas will need to meet.” The new fuel is called G100UL. Roehl said they have filed for a patent and have applied for certification with the FAA. He said representatives with the FAA, The Aviation Consumer magazine, and General Aircraft Manufacturers Association have come to Ada to look at the fuel they’ve developed. No ingredients in their formula should drive the cost of avgas up significantly, Roehl said.

“Our goal here is to preserve the opportunity for today’s aircraft engines to not only maintain existing aircraft performance levels but also to be able to raise those performance levels and improve the efficiency of those engines on a new unleaded high-octane fuel,” he said. Roehl said the fuel has been tested in their testing facility, as well as in one of their airplanes. After more testing, he and Braly hope the formula can be licensed to world-wide avgas producers. “We hope this fuel can be adopted as a replacement for 100LL and should serve to help the environment while maintaining the performance of our aircraft today,” Roehl said. “For 15 years since the lead was removed from automobile gas, the EPA has given an extension to the general aviation industry to allow them to continue to try to find some additive to try to replace tetra-ethyl lead which would allow for the removal of lead and yet the retention of the 100 octane rating of the fuel.” Roehl said no substitute could be found that provided the same octane rating. Roehl said there are approximately 200,000 airplanes currently flying in the world with piston aircraft engines—typically smaller single and twin engine airplanes. The standard fuel for these engines is called avgas, also known as 100LL (Low Lead). Roehl said tetra-ethyl lead is a major ingredient in the fuel. “It’s the last remaining leaded fuel allowed by the EPA,” he said. “As airplanes and engines are certified by the FAA (Federal Aviation Administration), the engines’ horsepower and performance is based upon the octane rating of the fuel. If you decrease the octane rating of the fuel, the engines cannot make the rated horsepower and the engines and the airframes in combination can’t perform according to their certification basis.” Roehl said they’ve tested several unleaded fuels others have formulated to try and solve this problem.

Cubdriver
02-23-2010, 10:55 AM
Embry-Riddle Tests Biofuel For Switch To "Green Fleet"

http://www.avweb.com/images-avweb/clearpixel.gif
2/22/10. Mary Grady, Contributing Editor. Embry-Riddle Aeronautical University, which operates the nation's largest fleet of airplanes in a college training program, said on Monday (http://www.erau.edu/er/newsmedia/newsreleases/2010/swift.html) some of those airplanes will soon be burning lead-free renewable fuels produced by Swift Enterprises (http://www.swiftenterprises.net/Swift%20Fuel.html). "We believe this effort by Embry-Riddle and Swift will guide the way to a large-scale switch by the general aviation industry to alternative fuels," said Richard Anderson, associate professor of aerospace engineering and chief investigator in the research project. Engineers at ERAU's campus in Daytona Beach, Fla., will perform the certification testing needed to enable more than 40 Cessna 172s, nearly half of the university’s fleet of 95 aircraft, to use Swift fuel. Embry-Riddle chose to partner with Swift because the company's non-leaded fuel has passed an FAA detonation test and gets more miles per gallon than current aviation fuel, the university said in a news release. The fuel can be synthesized from sorghum.

Small aircraft, which burn nearly 190 million gallons of aviation fuel a year, contribute 45 percent of the lead emissions in the nation's air, according to the Environmental Protection Agency. Removing lead from airplane fuel has been technically challenging, because lead prevents detonation in airplane engines, according to ERAU's news release. AVweb editorial director Paul Bertorelli recently tested another candidate for the fuel that will replace 100LL, G100UL, under development by General Aviation Modifications, Inc. Click here (http://www.avweb.com/blogs/insider/AvWebInsider_G100ULFlight_201973-1.html) to read his report and his opinions about the fuel.

Cubdriver
04-13-2010, 06:56 PM
SwiftFuel powers Seminole at Sun 'n Fun

4/13, Mike Collins, AOPA: A twin-engine Piper Seminole, registered as an experimental aircraft, is burning SwiftFuel during daily demonstration flights at the Sun ’n Fun International Fly-In and Expo. The 100SF fuel, developed by Swift Enterprises Ltd. (http://www.swiftenterprises.net/Swift%20Fuel.html) in West Lafayette, Ind., uses biomass such as sorghum and switch grass—instead of oil—to produce a high-octane fuel the company says could replace leaded avgas in piston-engine airplanes (see “Grass for Gas,” September 2009 AOPA Pilot (http://www.aopa.org/members/files/pilot/2009/september/fuel0909.html)). Erik Lindbergh, grandson of Charles Lindbergh, is serving as guest pilot on the flights, along with staff from Embry-Riddle Aeronautical University. “The future of general aviation is quickly evolving toward alternative aviation fuels,” Lindbergh said. “I’m delighted to be working with Swift Enterprises and Embry-Riddle to help solve the leaded fuel challenge for general aviation.” SwiftFuel does not use lead, ethanol, toluene, or oxygenates, and produces fewer pollutants than 100LL fuel—while providing 15 percent more volumetric energy, the company said. The fuel does not require any additives or stabilizers, and the company believes it could be “a near drop-in replacement” for today’s 100LL fuel.

Embry-Riddle Aeronautical University (http://www.erau.edu/) plans to phase in lead-free renewable fuel for its training aircraft, the nation’s largest collegiate fleet. Engineers in the Eagle Flight Research Center, a laboratory in the College of Engineering at Embry-Riddle’s Daytona Beach, Fla., campus, will perform the certification testing needed to enable more than 40 Cessna 172s, nearly half of the university’s fleet of 93 aircraft, to use Swift fuel. "Having Embry-Riddle come with us to Sun ‘n Fun, one of the premier airshows in the United States, brings credibility and attention to what we have been doing to ease the pressure general aviation has been under not only to get rid of leaded fuel but also to reduce the need for crude oil in the United States," said Mary Rusek, president of Swift Enterprises.

FAA targets 2015 for unleaded aviation gasoline

4/14 John Croft. CharterX (http://www.charterx.com/resources/article.aspx?id=6432). The US Federal Aviation Administration is planning to spend $10 million over the next five years to develop an unleaded aviation gasoline to replace the 100 octane low-lead (100LL) fuels used in piston-powered aircraft. The effort comes as the US Environmental Protection Agency prepares to issue an advance notice of proposed rulemaking to reduce lead emissions in avgas, the only remaining mobile source of lead in the USA, according the General Aviation Manufacturers Association. Included in the FAA's 2011 budget request, which has not yet been approved by the US Congress, is $2 million in research funding that will include engine ground testing of candidate unleaded fuels at the agency's Atlantic City technical centre. The FAA and industry partners, including GAMA, fuel companies and two universities, will also begin research into ways to modify high performance general aviation engines to run on unleaded fuels. While many smaller engines have been cleared to burn automobile gasoline, higher-performance engines require the tetraethyl-lead additive in 100LL to prevent detonation problems that can lead to engine failure. The FAA's ultimate goal is to develop a replacement fuel that will be transparent to the pilot, in terms of its delivery and use, with equivalent performance to 100LL.

Cubdriver
04-16-2010, 07:42 AM
EPA to comment on 100LL

4/09, AOPA ePublishing. The Environmental Protection Agency (EPA) is expected to publish an advance notice of proposed rulemaking this month about the environmental impact of leaded avgas. The notice will address a 2006 request by Friends of the Earth (FOE) that the agency propose emissions standards for lead from general aviation aircraft. The EPA will publish information about the use of leaded avgas and its effect on air quality, and will request comments on that information. The GA industry has been actively involved in developing a plan to transition to a new, unleaded avgas for piston-engine airplanes and will continue to work with the EPA on plans that are practical for GA. The FOE petition requested that the EPA find that lead emissions from GA aircraft may reasonably be anticipated to endanger public health and welfare—conditions that make those emissions fall under the Clean Air Act and give the EPA the authority to regulate them—and propose emissions standards under the Clean Air Act. In 2007, the EPA issued a Federal Register notice seeking comment on the FOE's petition. The agency said that it has concerns regarding lead exposure, particularly during childhood, and that leaded avgas is used at almost 20,000 airport facilities in the United States.


Industry groups prepare for unleaded future

4/22, AOPA eBrief. The Environmental Protection Agency has formally begun the regulatory process that may ultimately lead to standards mandating general aviation's transition to unleaded avgas. The EPA issued an advance notice of proposed rulemaking (ANPR), a preliminary step in the process required by the Clean Air Act for the EPA to establish standards for lead emissions from avgas. The ANPR gives the GA community an opportunity to comment regarding the possible new environmental standard and the development of a plan for identifying, evaluating, and ultimately transitioning to an unleaded fuel, several industry groups said in a joint statement April 21.

AdamFrisch
05-05-2010, 06:26 PM
You guys might want to check a thread I started about electric/hybrid aircrafts at the Pprune forum last year. It has some interesting postings.

Here's the link: I can't wait for electric/hybrid aircraft. - PPRuNe Forums (http://www.pprune.org/private-flying/400967-i-cant-wait-electric-hybrid-aircraft.html)

But just in case you might not care to go there, here's my initial posting and some added facts:


I can't wait for electric/hybrid aircraft.
Half of the threads here pertain to safety and high workload related issues connected to the antiquated way modern aircrafts are made and propelled.

Just below is a thread about a C152 engine quitting because of either a rich cut or carb ice, depending on who's answering. Not even injection engines are commonplace even though the offer more security. Cessnas new 162 Skycatcher? Carb - check.

Just imagine if the above aircraft were hybrids. Until the new nanowire batteries get powerful enough in the meantime a hybrid solution with a small turbine APU would recharge a LiPo battery (like they've had and broken all records with in the R/C world for the best part of 20 years now). The battery runs a brushless electrical motor with 90% efficiency compared to the 20% efficiency of the combustion engine. Just imagine all the benefits:

1. No carb ice.
2. No need for complicated constant speed props (as electrical motors have linear power output and no sweet spot).
3. No TBO - only limited by bearing life.
4. No CO poisoning.
5. No shock cooling.
6. No rich cut.
7. No degradation at altitude, no need for turbos etc.
8. Built in Fadec (brushless motors you set a RPM setting and it keeps it through the controller, no matter what).
9. No need to check oil.
10. Much less weight - 15Kw (21hp) R/C brushless weighs less than 2kg. That means that a O-200 replacement would weigh about 10kg. That leaves a lot of weight for a battery..
11. No dirt.
12. No vibrations.
13. No noise.
14. No leaning at altitude.

I want to enjoy flying and the view, not manage a steam driven 100 year old system just looking to screw me up.

I can't friggin' wait.

And here's a bit more meat:

But the beautiful thing with a hybrid is that you could take off on battery power, climb to your cruise altitude and throttle back to economy cruise (which on an electric is probably well below 50%). Now you start the APU. This ensures that the APU will be running at a higher altitude and consume less fuel. And all it needs to power is the economy cruise. It will also reduce noise considerably for take off. As you descend you windmill and generate electricity to top batteries up a bit. And should you really need to get down fast, you just regen more and make the prop/fan work as a speed brake.

But sure, there are still obstacles to be overcome for a pure battery powered tourer. But they're closer than many think. Battery capacity has doubled in just 5 years.

I've researched this quite extensively and what's important is power density, i.e. Wh/Kg. Newest LiPo batteries (like the R/C guys use) deliver about 400Wh/kg today. That means you could run a motor at full power of 400W for one hour. Or to put it in perspective of a C152 - a 182kg battery pack could make you cruise at 100% for one hour. In reality, you would never use 100% all the time on electric motors, so the endurance would probably be closer to 2 hrs for that weight. Not that far off - remember, you'd save not only on the weight of the fuel and the engine and that's gotta be an easy 150kg alone.

Now, here's the interesting thing - nanowire batteries that have just been patented and are getting geared up for production have a potential power density of 4500Wh/kg. If they can deliver on that promise, then it's all over for the combustion engine. Bye bye. Gone.

Obviously cost is also a factor for batteries, and to keep them healthy no more than 1000 charges are recommended. At the price of batteries today that would be a large sum of money, probably the equivalent to a TBO overhaul of your Lycoming. But the nanowire promise has the added benefit of dramatically reducing the price as well.

It's closer than we think. I wouldn't want to be Rolls Royce, General Electric, Pratt & Whitney, Lycoming or Continental in 20 years time.

Food for thought. I'm am absolutely certain that electric is the future for aviation.

Cubdriver
05-09-2010, 06:27 AM
Thanks for sharing your interest in this topic, I love tech topics also. I keep up on the technical news and occasionally I have thought about including electric topics here as well. They seem to have an application to certain unmanned science and surveillance aircraft and to light sport airplanes, for which they are ideal. The immediate future is in unleaded gas and possibly biofuel. My understanding is the pure electric is ideal for use in light sport airplanes. It's a lot like the choice you have with surface electrics: electric works and works well as long as you stay a limited distance from power. It has numerous positive qualities like reliability, responsiveness, quiet, and so on. But you also have to trade speed for endurance in a severe balance. You can go fast with lots of acceleration, or you get enough endurance to go some fraction of the distance of gas. Therefore it is not mature technology until a better battery is designed. Electric is very good for use in light airplanes for flying without the roar of the engine. Electric powerplants have many other great qualities as you know. The future is bright for electrics, no doubt about that. However, there needs to be a breakthrough in battery technology before they are competitive with combustion.

The hybrid is an attempt to alleviate the battery limitation by letting some gasoline ride along with higher energy density. It's not a bad idea for small airplanes and it certainly could be done, but hybrids will have to go through an enormously expensive development-certification cycle, one the GA consumer cannot support. We first need to solve the unleaded gasoline problem then we can think about other engines. Cheap gasoline motors brought the wonder of flight to the average working person but even without the cost of developing a new powerplant GA airplanes have gone beyond the reach of the average consumer. The light sport airplane is an attempt to remedy this problem. So, while it may be technically possible to engineer a hybrid airplane and we already actually have electric LSAs, the hybrid-electric GA airplane in 4 to 6 seats would almost certainly be a miss owing to cost. Engineers have to look at cost in order to propose a development program. You would have to sell many more airplanes than GA manufactures in a given time to make back the cost for development.

AdamFrisch
05-09-2010, 03:41 PM
Thanks.

It's a topic close to my heart.

You're absolutely right that the technology is all there - all we need now is the energy storage capacity in batteries. As I mentioned, that progress is happening and battery capacity doubles every 5 years. Even being very conservative (not considering the newer patents for nanowire and equivalent high density storage) with the 400Wh/Kg that we have today, it would only be about 20 years until we're in the region 3200Wh/Kg. That's enough to start hammering the nails into the coffin of fossil fuels.

Let me just give you some examples:

Fuel has about the equivalent of 12000-20000Wh/kg in theoretical energy density per litre. But since combustion and turbine engines are so inefficient in turning this into thrust, only about 20-30% get to actually work. That's about 3600-4000Wh/Kg. Electrical however turns about 90% of the power stored into work, so they meet around here in figures.

However, in the meantime and until the power storage has been solved, hybrid is an interesting bridging technology. And in my view the development and certification obstacles should be less stringent than a certification for a new engine. Because, after all, with a hybrid system you have redundancy. If the batteries fail - you power the electric props/fanjets or whatever directly from the APU. Likewise, if the APU fails, you have enough juice in your batteries to make your safe alternative or deviate to another airfield.

jungle
05-09-2010, 09:55 PM
Just let us know when those batteries can equal the energy of 350,000lbs of JetA1 at the same weight. I suspect that is a very long way off, perhaps never. Using electrical energy to produce high density hydrocarbon liquid fuels is currently both possible and a more likely alternative.

AdamFrisch
05-09-2010, 11:57 PM
In a macro perspective drilling for oil, shipping it across the world on boats, pupming it into refineries and ground transporting it out to aircraft who then turn only 20% of it into actual working power, is just about as inefficient as you can get. The infrastructure for electrics is already there and readily available. What's even better, it's already been paid for.

There's been a lot of talk of electric taking over for the last 100 years and not much has come of it. But i truly believe we've now turned a corner. 1 million sold Priuses and hybrids in every manufacturers pipeline is a sign of that. Just look at the R/C field where electric power has totally trashed all records in both speed and performance. Gas powered doesn't stand a a chance and can't even compete in the same category. Granted, endurance is not what's needed in R/C flying at the moment, but that will come with better capacity.

If it can happen there, it will happen in GA.

TonyWilliams
05-10-2010, 02:18 AM
Aircraft engines operate at a higher percentage of their total operating range. Airplane at cruise= 85% or more of total RPM range, versus a car cruising down the highway may be at about 35%. Agreed.


I don't know how many times I've read this, or heard this. Not an apples to apples comparison. The actual RPM's are similar. My car cruises at 2300 rpm, just like the plane. It's the percentages that, while accurate, are intentionally misleading.

"Car" engines are virtually always measured and advertised for PEAK or MAXIMUM horsepower that it can produce. Horsepower being a measurement of torque, and multiplied by RPM, in it's simplest form (there are many world standards for this, but the basic theory remains). Twisting force, measured over time.

If you were to spin the Car engine faster than it's maximum horsepower, it will actually make LESS POWER. For the typical RATED horsepower engine, like an airplane piston engine. If you were to spin one faster than the RPM with which it is RATED for it's horsepower, it will generally make more power (until the dinosaur engine blows up, or it reaches its PEAK power, if it's still running at all).

Any industrial, mostly steady state engine will have a similar rating.

If I had two identical sized engines, say an unmodified Lycoming 360 and a Chrysler 360, they would make very similar power at 2700 rpm. But, the water cooled 8 cylinder Chrysler will be much, much heavier, and WAY cheaper (mostly do to mass production and no FAA certification), than the limited production, air cooled, 4 cylinder Lycoming. That 2700 rpm is 100% for the Lyc, and maybe 40% for the Chrysler. Same power, same size cubic inch displacement engine, vastly different %'s.

I wouldn't even want to guess how much money you'd have to spend to make that same Lycoming stay together at the RPM and Horsepower level that can relatively easily be produced by the Chrysler.


Taking the lead out will destroy 30% of the piston engine aviation fleet, which may seem to be a good solution when you're at the end of a 4 day trip. :) This exact strategy used by Detroit in the 1970s to dispose of most of the existing cars that ran on leaded gas in previous ages. But do you as the owner of a brand new $50,000 Lycoming TIO540 airplane want the engine destroyed in say, five or ten years while the rest of the airplane is perfectly fine? Of course not, and this is why there is a big fuss being made over finding a "drop in" replacement for leaded avgas.


Destroyed?????? Come on. That TIO-540 could be derated overnight in any number of ways to continue operation in a "worse-case" scenario.

The compression ratio could be lowered, relatively cheaply with a piston change. The turbocharger manifold pressure could be reduced. The ignition system could be modified.

Jet engines typically take off at some "flex" or reduced setting. Adopt a similar strategy for pistons. That would be a short term answer if lead was lost tomorrow, and mostly a paperwork exercise. Yes, there may be some short airports that won't be available.

The reality, however, is that compression and manifold pressure could probably stay the same, and virtually everything fixed with ignition and fuel delivery, at the same or even slightly increased power at less fuel burn... JUST LIKE CARS, MOTORCYCLES, AND THE REST OF THE WORLD !!!!

The piston aviation business drags its feet to advance engines at its own peril, in my opinion. You can fill in all the reasons why, but the fact will remain.

Cubdriver
05-10-2010, 09:20 AM
If you are making the point that these two types of engine are different in several ways, I tend to agree. But they are mighty similar as well, specifically, typical dyno curves (http://www.google.com/images?um=1&hl=en&client=firefox-a&rls=org.mozilla:en-US:official&tbs=isch:1&sa=1&q=crate+engine+dyno+curves&aq=f&aqi=&aql=&oq=&gs_rfai=) for these two engines are similar even if the airplane engine stops revving at 2700 RPM while the car engine keeps going. But this does not shoot any holes in the percent-of-design-RPM-operating-range analogy. Yes, they have different approved RPM operating ranges and each is designed with its own range. However, many authorities on the subject seem to think the percent-of-RPM-operating-range analogy is valid. You suggest that airplane engines are not as strongly built as car engines, probably so. They are optimized for light weight with a fairly low limit on upper RPM range. If you rev them beyond their approved operating range they self-destruct. But they are strong enough for their approved operating range, and they are used at a high percentage of it as well. To say the designs are somewhat different is correct, but this does not serve to nullify the present analogy.

Nothing I said above is comprised of my own opinion. Your statements about certification and poor economies of scale adding much to the cost of making of airplane engines or even tweaking them against knock, is quite true. But to broadly say the airplane engine industry drags its feet on purpose is faulty. They would love to mass produce airplane engines like Ski Doos and Toros and put a couple of airplanes in every yard. Airplane engines are held to higher standards than car engines and even tweaking them with piston of cylinder head swaps costs far more in terms of certification and manufacturing than for the same in a surface vehicle. Same technology, different cost. If you are saying it is intentional on their part to stay behind the other manufacturing camps, well I doubt it. They go where the FAA allows and the money is the best. If there is price rigging going on here, I would say to blame it on the FAA.

Cubdriver
05-17-2010, 10:22 AM
Durban company flies high on biofuel: Durban company has unveiled a light aircraft engine which can operate on biofuel or liquid petroleum gas.

[See also previous article here (http://www.airlinepilotforums.com/technical/38787-future-fuels-ga-3.html)]

(5/17, Sapa, Times Live) "Our technology benchmarks South Africa against the finest aviation engineering in the world,” said Andre Schoeman, chairman of ADEPT Airmotive, the company that developed the engine. The liquid-cooled engine, with advanced electronic engine management, was launched at Virginia Airport in Durban.It was fitted to a South African designed SA Ravin 500 light aircraft.The department of science and technology invested R10.5 million to fund ADEPT Airmotive to a pre-production stage.“Through investment in local research and development, it is fair to say that ADEPT is providing the catalyst for a genuinely world class general aviation manufacturing industry,” said Schoeman.He said the engine produced 320 horsepower, and boasted the lowest lead, nitrous oxide and carbon dioxide emissions and noise levels. United Kingdom based AgustaWestland Helicopters also provided financial support to ADEPT's certification process through the European Aviation and Safety Agency (EASA).

TonyWilliams
05-17-2010, 03:10 PM
Yes, they have different approved RPM operating ranges and each is designed with its own range. However, many authorities on the subject seem to think the percent-of-RPM-operating-range analogy is valid.


They think it's valid because they are absolutely correct. Aircraft engines operate at up to 100% of rated power.

If I used the above example of a Lycoming / Chrysler 360 cubic inch engine; if they RATED the Chrysler's horsepower at 2700 rpm just like the same cubic inch Lyc, now we have a more "apples to apples" comparison.

It's a paper exercise to hopefully more clearly make my point. But in reality, Chrysler DID make (not sure about now) "Chrysler Industrial" engines based specifically on their auto versions, that were flat rated JUST LIKE AIRCRAFT ENGINES. Same hunk of cast iron as an engine in a car, with typically a few simple modifications like stellite valves, hardened valve seats, more robost torsional dampening, etc.

With both of the above referenced engines at "100% power" at 2700 rpm, I'm not so sure which engine would last longest. My money would be on the liquid cooled engine with modern fuel and ignition. There's no magic in a Lycoming. It's crude, simple, very old technology. Noisy, high on vibration, couldn't pass an auto emission test no matter what, very expensive, and light enough to be used in airplanes.

Cubdriver
05-17-2010, 04:13 PM
Several people have expressed various shades of doubt on this thread that the FAA, Continental, Lycoming, and various parties are honest and forthwith. In this case the concern is that certain airplane engines, usually higher compression 6 cylinder models will not operate reliably on unleaded gasoline and therefore cannot be approved for it. This could be a conspiracy attempt on their part. There also may be aliens living among us, which is the beauty of any conspiracy theory in that you really don't know. The suspicion usually is along the lines that these agencies want to retard the development of new airplane technology, keep prices fixed, keep automotive suppliers out of the business, disallow Mogas from airplane use, and of course always go unchallenged. So if it boils down to a matter of trust as far as what these so called aircraft authorities say, then I guess I trust them. Maybe they are erring on the side of caution and maybe you can drop a couple of $900 AutoZone rebuilds into your Beechcraft Baron, burn Mogas all the time, spend the other $49,000 on a backyard pool and all will be well between you and the airplane. But it's really not for me to say. I certainly cannot contradict established experts without some pretty strong evidence to back it up. As of now, the latter are saying that we need a substitute for leaded Avgas for certain airplane engines.

rickair7777
05-17-2010, 04:20 PM
My old watercooled japanese sedan cruises at about 3000 rpm, it has 190K miles, and well on track to make it to 250K. At an average 50 mph, that's about 3800 hours without a mechanical hiccup.

Aircooled VW's usually last about 100K (if you take care of them). Assuming an average 50 mph and 3000 rpm (also pretty typical), that's 2000 hours. Sounds familiar?

The only two advantages to aircooled engines are weight and mechanical simplicity, which translates to more reliability with respect to fewer things which can go wrong.

The big disadvantage AC engines have is tolerances...for max wear longevity you want parts machined to very tight tolerances, just enough to allow for the needed oil film but no more. Loose tolerances allow parts to flop and bang
around (especially at high RPM or load) drastically increasing wear.

Since different materials and sizes of parts expand at different rates, there is only one temperature where any two parts will have the ideal fit with respect to each other.

With a WC engine, you design the parts to be at the ideal tolerance at normal operating temp (NOT). When you start the car, it is not at NOT so there is potential for flopping around. That's why you should go easy until the car warms up. After 5 minutes or less, the WC engine is at it's NOT with ideal parts tolerances and there it stays. The colling system maintains NOT under a wide variety of laod and OAT conditions by adjusting coolant and air flow and/or The only way to screw that up up is by seriously overheating the engine.

But the AC engine does not get to stabilize at a consistent temp, normal load and OAT variations mean that there is wide potential range of "normal" operating temps. If you design the tolerances to be ideal at some median OAT and load, they would be too loose or tight under other conditions. Since loose is better than too tight, an AC engine under typical conditions is operating with loose tolerances which means more wear than a comparable WC engine.

Aircraft engines have an advantage in that they spend more time at a predictable rpm than a auto engine, but they still have to allow for T/O power on a hot day (or flight training ops).

Modern design, manufacturing, and QA techniques (and synthetic oils) have almost eliminated random mechanical failures so the simplicity of AC engines no longer counts for much. A WC engine is probably more reliable for abuse operations like flight training.

There is still weight savings but I think as WC airplane engines become the norm we will find that higher TBO's and fuel efficiency offset the benefits of lighter AC engines.

Cubdriver
05-17-2010, 04:35 PM
Rick, all that is true, but the single largest problem facing aircraft engine manufacturing is the poor economics of making a new model. You are going to make a new aircraft engine at an enormous cost of development and then sell maybe 5,000 or 10,000 of them total. By contrast, the engine in my Nissan Frontier is the VQ40 model, and the VQ series (http://en.wikipedia.org/wiki/Nissan_VQ_engine#VQ40DE) in some stripe or other is used in an enormous number of brands, sizes, models, and even multiple countries. Nissan will sell literally millions of these engines before moving on to the next design. So its not really a matter of design or even willingness to design something better, it is a matter of economics.

TonyWilliams
05-17-2010, 05:54 PM
I certainly cannot contradict established experts without some pretty strong evidence to back it up. As of now, the latter are saying that we need a substitute for leaded Avgas for certain airplane engines.

the single largest problem facing aircraft engine manufacturing is the poor economics of making a new model. You are going to make a new aircraft engine at an enormous cost of development and then sell maybe 5,000 or 10,000 of them total. So its not really a matter of design or even willingness to design something better, it is a matter of economics.


Obviously, lead needs to be removed from the gasoline that we use. It should have been done a long time ago, and it will get done. And all the excuses will look pretty lame as to why it didn't happen sooner.

Besides cost of aircraft engines based on scale of production, the government certification is probably the single biggest cost. Both become economic.

Experimental aircraft that use non-certified engines that can burn unleaded gas do so at a much cheaper price, because they typically use cheap mass produced engines that are already designed for unlead gas, and because the government hasn't increased the cost through certification.

Hopefully the LSA class will remain closer to the experimental class than the "certified" one.

By the way, these "certified" Lyc's and Continentals have no problem "blowing a jug" or otherwise failing quite spectacularly. I'll take a Toyota design (they did certify a V-8 engine in a Navajo and a Malibu, if I recall correctly).

rickair7777
05-17-2010, 08:07 PM
Rick, all that is true, but the single largest problem facing aircraft engine manufacturing is the poor economics of making a new model. You are going to make a new aircraft engine at an enormous cost of development and then sell maybe 5,000 or 10,000 of them total. By contrast, the engine in my Nissan Frontier is the VQ40 model, and the VQ series (http://en.wikipedia.org/wiki/Nissan_VQ_engine#VQ40DE) in some stripe or other is used in an enormous number of brands, sizes, models, and even multiple countries. Nissan will sell literally millions of these engines before moving on to the next design. So its not really a matter of design or even willingness to design something better, it is a matter of economics.

I know, but I think there may be potential for conversion of stock LC auto engines to aviation applications...I think both Diamond diesels are based on automotive plants.

TonyWilliams
05-17-2010, 08:10 PM
I know, but I think there may be potential for conversion of stock LC auto engines to aviation applications...I think both Diamond diesels are based on automotive plants.


Mercedes Benz.

Cubdriver
05-20-2010, 03:50 PM
It's expensive and troublesome adapting car engines to aviation even ignoring the certification cost. Problems are operating altitudes, heat and cooling, loading differences, RPM, fitting the engine inside a cowling, making it compatible with a variety of existing aviation components (vacuum pumps) and so on. It's a lot of things to work out. It adds up.

As far as certification is concerned, people do not realize what is involved with the costs a company must pay if it wants an engine to be certified for aviation beyond experimental and light sport segments. Part of it is FAA lab charges to put the engine on a stand and a few airframes to show it works as advertised. But what people do not realize is that every single part in the engine must also go through an applicable certification process. These costs are placed well upstream of the engine manufacturer in most cases. Such costs reflect the expense of keeping an elaborate paper trail showing extensive details on raw manufacturing stock, finished component testing, adherence to standard for equipment used in manufacturing, and all associated costs such as maintaining records for decades. Aerospace manufacturing is replete with manufacturing controls, tests, paperwork, and regulations not found in automotive manufacturing. This is one of the reasons things change so slowly in the aerospace industry, and are the reason general aviation moves so slowly.

-----------

Continental Motors Reveals Jet-A-Burning Piston Slapper

FLYING eNewsletter (5/20/10) Teledyne Continental Motors (TCM) has unveiled a two-engine project that will bring jet fuel to the light-aircraft industry. The first, a 230-hp four-cylinder engine is expected to be certified next year. A follow-on six-cylinder, 350-hp version could follow as soon as two years later. TCM said the engine program stems from acquired technology — but would not identify which European company the already certified engine technology came from. (According to an article on AvWeb, the TCM engine bears a striking resemblance to the SMA SR305.) Under the license agreement with the original maker, TCM now has free rein to further develop the existing engine as it sees fit. The company has said it expects the new engines to cost not much more than their gasoline-burning counterparts in the same power range. TCM's version is currently undergoing tests on a static test stand and in flight on a Cessna 182 Skylane. Specific fuel consumption (sfc) of the new engines is said to be in the .36 range.

Kerosene Engine Certified in Europe

(AOPA ePilot, Alton K. Marsh, 5/28) Centurion has received a supplemental type certificate (STC) for the installation of the 155 horsepower Centurion 2.0s kerosene-fueled, piston engine in the Cessna 172. The European Aviation Safety Agency (EASA) issued the STC to Centurion, the subsequent sales company to the insolvent Thielert Aircraft Engines GmbH. Cessna models 172F to S can now use the engine. First deliveries begin in June. Certification is expected soon for the Robin DR400 Ecoflyer and Diamond DA40 TDI. The Centurion 2.0s is the more powerful version of the well-established Centurion 2.0. With an identical weight, it generates an additional 20 hp. “Everyone who was impressed by the flight performance of the Cessna 172 with the Centurion 2.0 will be enthusiastic about the Centurion 2.0s,” said Centurion CEO Jasper M. Wolffson. With the Cessna 172S model, the new engine increases the maximum takeoff weight limit from 2,450 pounds to 2,550 pounds. Cruising flight fuel consumption is 6.4 gph at a speed of 115 KTAS (at 70 percent power, 6,000 feet). The takeoff distance over a 50-foot obstacle using the Centurion engine is 1,617 feet. The range with the 44.5 gallon standard tank is 665 nautical miles.

Cubdriver
06-10-2010, 09:39 AM
Lycoming and Continental Differ on 100LL Replacement

(FLYING eNewsletter, 6/09) According to a story posted on Avweb, Lycoming has gone on record opposing the development of 94UL as a replacement for 100 low lead (100LL) aviation gasoline. Continental supports development of 94UL, and is currently experimenting with modifications to its engines to accommodate the lower octane level — approximately 8 octane points less than leaded fuel. Both engine manufacturers acknowledge that many of their engines will perform satisfactorily on 94UL, but the higher-power, higher-compression engines are problematic. Computerized ignition (IE2 from Lycoming; Powerlink from Continental), knock-sensing technology and in some cases, lower-compression engine overhauls are among the fixes proposed to bring older engines into line with reduced octane levels. But Lycoming warns that the drop in fuel octane cannot be made up without potentially serious impact on engine performance. Lycoming believes that 100-octane lead-free aviation fuel is an attainable goal and should be pursued.

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AOPA Videocast

AOPA Videocast: Issues with Leaded Avgas
(http://www.aopa.org/advocacy/articles/2010/100610avgas.html?WT.mc_id=100611epilot&WT.mc_sect=adv#ooid=01OXFnMTph2q3pcOS3uh-yDk7c4TpypB)

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Notes on Above VideoCast: Issues with Avgas.

Why do we need to replace 100LL?

-30% of the piston fleet need high octane fuel to prevent engine knock and detonation
-that 30% actually uses 70% of the avgas consumed
-many commercial piston aircraft like the DC-3/4/6 series need higher-octane fuel
-70% of the fleet may not need it, but it is not practical to have two fuel grades
-EPA demands it for the environment (lead is a proven carcinogen)

What does a suitable replacement for 100LL need to do?

-have good cold and hot start behaviors
-have similar weight to 100LL
-be affordable
-have good freezing point
-have stability over time
-not leave post-burn deposits
-provide octane sufficient to prevent detonation
-be cheaply and easily manufactured
-be transportable
-be environmentally friendly

How soon is an avgas replacement coming?

-it is too early to make a decision now (ie. Swift, UL94, engine modifications, etc.)
-the solution may not include only a fuel swap; it may include engine modifications to reduce detonation
-when all issues (economic, technical, and certification) are answered
-FAA has the final say

What are some problems with going to a new avgas?

-avgas refiners refuse to make more than one grade of avgas, because the volume is small. Shipping, refining, and tanking all costs money and avgas represents only around 0.5% of all transportation fuel sales.

Cubdriver
06-17-2010, 03:44 PM
Here's an opinion piece from AvWeb that speaks to the same issues we have been knocking around here in this thread. Namely, why are small airplane engines so backwards technologically, and why not drop car engines into piston airplanes and get all the advantages accruing a modern car engine. He basically says the same things I say on this subject. 1) The economics of new engine development do not justify the investment, and 2) it has already been tried and it repeatedly fails.

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Fuel crisis: What We Really Need Is...

(Paul Bertorelli (http://www.avweb.com/blogs/insider/AvWebInsider_DumbEngineCompanies_202741-1.html)/ AvWeb 6/17/10) The companies that build aircraft engines—and for the purposes of this discussion, let's call them Continental and Lycoming—are staffed by the dumbest people on the planet. This would be the general gist of opinions of pilots who know automotive technology and who also own or fly airplanes. To them, the ongoing discussion about finding a replacement for 100LL is simply a failure on the part of the Big Two to freely adapt the advanced engine technology that's out there for the taking. There are various reasons why these companies haven't done this, but for us experts sitting on the sidelines, the general thinking seems to be that they could do this. They just have chosen not to. The reality is different. And it's not a question of understanding and adapting technology because the automotive engineers who can do this work are readily available. Some of them even work at Continental and Lycoming. Some are pilots, too. The challenge is to find enough buyers to actually construct a business plan that won't crater within, say, five years. This is another way saying buyers say they want one thing, but when presented with that very thing, they demure...

TonyWilliams
06-17-2010, 05:59 PM
So, what I gather from Paul's article is that the technology isn't bad in cars, or not adaptable, but just not economically viable.

I'd agree. Because the hoops to jump through would be HUGE to certify such an engine, even though the "certified" ones have any number of HUGE problems.

Look at the AD lists for some of these. Look at the SDR's, and all the parts that are sold to repair these engines. Swapping "jugs" on piston aircraft is almost sport on some models. Dropping valves, breaking crankshafts, grinding of cam lobes, oil pumps that sheer off and quit, cracked crankcases, mechanical magnetos failing in any number of ways, cracked exhausts burning the wing off (admittedly rarely part of the engine package, but instead the airframe mfg "engineers" these). And I'm just touching the surface of all the "features" of these FAA certified masterpieces.

I agree that the decades of advancements in the piston engine world (not just cars, for sure) would be difficult to economically bring to the piston aircraft world.

Not technical... economic. And the single largest cost might just be the certification effort that motorcycles, boats, cars, trucks, lawn mowers, farm equipment, etc, don't have to engage.

And please have Paul answer this question; if the conversion of automotive engines "can't" be done for whatever reason, why is it being successfully done now with Mercedes Benz diesel engines?

Cubdriver
06-18-2010, 02:38 PM
Right, he didn't say it can't be done it's just that for various reasons it isn't economically viable. Right off hand, I do not know how Diamond managed to work the numbers on their Benz diesel conversion because they obviously do not sell more than a few hundred DA-40's with those diesels per year. I cannot imagine it is paying for itself. I suspect they are losing money so they can keep existing airplanes in the fleet going and retain customers. If you know otherwise, I am all ears. They are not going to show the balance sheet anyway, so we will never know. But one thing is for certain- multiple attempts to put automotive engines in airplanes have transpired and they never really work because of FAA certification costs and the overall poor payback on the deal.

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Cirrus Prez Comes Out Against 94UL

(Brent Wouters, 06/17/10 Cirrus Aircraft (http://news.cirrusaircraft.com/post/2010/06/17/A-LETTER-FROM-BRENT-WOUTERS-CIRRUS-PRESIDENT-CEO.aspx)) Cirrus Aircraft Community, Recently there has been much industry discussion regarding the future of 100LL aviation gasoline, the likely transition to an unleaded aviation fuel in the future and the possible impacts to owners, operators and general aviation industry health of a future fuel. While this subject is by no means a new issue, the recent Environmental Protection Agency (EPA) issuance of an Advance Notice of Proposed Rulemaking (ANPR) regarding lead content in aviation fuel formally initiates a regulatory decision-making process and has increased awareness of this topic and its potential future impacts. Cirrus has been actively working on this fuel issue for many years now and we are integrally involved in the industry leadership team working with the EPA, the FAA, and avgas producers. Simply, we are aggressively focused to achieve the very best path ahead and Cirrus will ensure that this path will keep your aircraft flying with the minimum possible transition and operating costs...

rickair7777
06-19-2010, 07:13 AM
My understanding from the engine industry perspective (I used to do LARGE engines) is that the cost is not so much FAA certification. The FAA exists to advocate as well as regulate aviation, and a lot of local FSDO jobs will be N/A if GA continues it's gradual decline. They do not have an incentive to be obstinate and kill the golden goose.

The actual hurdle is the technical development cost for a clean-slate engine. This is very high for a modern engine design, and the potential ROE would be too low for a GA engine unless you take a VERY long term view like 30+ years. Unfortunately modern managers are only interested in next quarter's stock options, and are not likely to look further than 3 years out...they won't be around to reap the long-term benefits.

An automotive conversion offers a few advantages...the basic nuts-and-bolts level engineering and testing is already done, and you have an extensive operational history to build from. All you have to do is add a few aviation specific tweaks, and off you go. The downside is that the engine was not optimized for aviation originally, and without massive re-engineering, probably never will be as efficient as a clean-slate design.

Also your options are probably limited to a tiny handful of auto engines which just happen to have a design close enough to you need for an airplane. And if the OEM stops making the engine, the aviation demand will not be high enough to sustain production, at least at an economical cost. You could easily end up starting all over if your source auto engine becomes unavailable.

TonyWilliams
06-19-2010, 12:27 PM
conversion because they obviously do not sell more than a few hundred DA-40's with those diesels per year. I cannot imagine it is paying for itself. I suspect they are losing money so they can keep existing airplanes in the fleet going and retain customers. If you know otherwise, I am all ears.


I don't know if the engines turn a profit, or not. But, it is being done, "successfully". Maybe they are losing their butts on this... if so, why not just use the Lycoming engines that they already have certified?



Cirrus Prez Comes Out Against 94UL

I didn't see anywhere in the article where they were against 94UL.

TonyWilliams
06-19-2010, 12:35 PM
And if the OEM stops making the engine, the aviation demand will not be high enough to sustain production, at least at an economical cost. You could easily end up starting all over if your source auto engine becomes unavailable.


Many very popular engine designs are produced and can be purchase wholly, or in parts, from outside vendors.

Volkswagen, Chevrolet and even Lycoming engines are a few examples. I doubt you can do the same with a Mercedes diesel, but that doesn't prevent a company from "cloning" the design after if has become obsolete for MB.

Buy it "cheap" now, get the certification, then over the years, piece by piece, reproduce all the various parts, waiting for the day that MB pulls the plug.

Then reproduce the thing for the next 50 years, like Cont / Lyc do !!!!

Cubdriver
06-19-2010, 05:07 PM
Rick- thoughtful comments as usual.

Tony-

94UL is 100LL Avgas, without the lead for octane boost. The lead additive is there against detonation, it boosts the octane to 100 so the engine doesn't kill itself. Bear in mind Cirrus sells only high-octane piston engines, they have a lot of skin in the game, they know that 94UL no-lead is not going to work in their airplanes. Money and sales are at stake. Cirrus president calls a meeting with the top propulsion engineers and asks: I need an answer as to whether or not we are cool with 94UL ruining all our engines because now is the time to go public on it. The engineers say heck no, meeting over. He goes out on a limb the following day with:

Cirrus President (http://news.cirrusaircraft.com/post/2010/06/17/A-LETTER-FROM-BRENT-WOUTERS-CIRRUS-PRESIDENT-CEO.aspx) "...let me be clear: Cirrus Aircraft does not believe that a 94UL solution is desirable for its owners or the health of the industry, and will strive for a better replacement fuel..."Corporate presidents are for politics and photo ops. This statement is an early attempt by a vested interest to steer the government decision on which fuel will receive approval as a replacement for leaded aircraft gas. I favor a government subsidy for biofuel and I realize it is a dreadful solution. The loan payback would have to be spread out over many decades with an appropriate return on investment. Many do not believe government should be paying for things a free market economy should produce. The problem is, there is no free market-driven interest in the short term to protect the environment. When the EPA finally trumps the FAA on the issue of when the lead has to go and finally sets a deadline, which they are threatening to do now, I do not think the market will be able to respond agreeably to diminished airplane sales resulting from jacked airplane prices. It will have to be subsidized until the cost is spread such that the buying public can still buy an airplane that costs about as much as it does now.

TonyWilliams
06-19-2010, 08:20 PM
Tony-

94UL is 100LL Avgas, without the lead for octane boost.


I'm actually reasonably familiar with the fuel, and the principles promoting the fuel. Even spent a few dollars on some of their products in the past 20 years.

Cirrus sells only high-octane piston engines, they have a lot of skin in the game, they know that 94UL no-lead is not going to work in their airplanes.


The principals promoting the 94UL would say otherwise. It works, and works well. Now, we're playing politics where science should prevail.


I favor a government subsidy for biofuel and I realize it is a dreadful solution.


The 94UL solution does not require this. Biofuel is a whole 'nother animal !!!

Cubdriver
06-20-2010, 04:39 AM
I will not be so silly as to take a firm position on anything that a large consortium of interests is uncertain of, a smorgasbord of interests ranging from regulators to manufacturers to universities to refiners to pumpers to users. Yet you seem certain the solution is to just drop the lead and keep on going as though nothing happened because it works in some airplanes and one supplier in particular is pushing it? Care to enlighten us?

rickair7777
06-20-2010, 07:54 AM
Many very popular engine designs are produced and can be purchase wholly, or in parts, from outside vendors.

Volkswagen, Chevrolet and even Lycoming engines are a few examples. I doubt you can do the same with a Mercedes diesel, but that doesn't prevent a company from "cloning" the design after if has become obsolete for MB.

Buy it "cheap" now, get the certification, then over the years, piece by piece, reproduce all the various parts, waiting for the day that MB pulls the plug.

Then reproduce the thing for the next 50 years, like Cont / Lyc do !!!!

The hardest part to reproduce is the block. And unlike auto clones, each aftermarket manufacturer would need FAA PMA approval. If you are planning on buying clone parts from two dozen different detroit aftermarket outfits they would ALL need to obtain FAA authorization. Not likely, only a few detroit autoparts suppliers have had any success breaking into aviation for that reason. If you ask them about AS9100, and they go "Huh?"...it's not going to happen.

CrimsonEclipse
06-20-2010, 10:17 AM
The future AvGas debate fascinates me.

It's a declining market for several reasons.

The first concern is the fuel producers. Last I recall, there was only one AvGas refinery (is this still true?) which constrains supply and vastly increases the price of an already expensive fuel.

A second concern is the technical viability of the 94 octane for EVERY engine. Cirrus is mentioned repeatedly, but what about the owners of C414 C421 and similar turbocharged pistons what would become worthless without massive modification? Many of these are still work horses for local economies.

Is their only remaining option to invest in a PT6 or hope for an inexpensive Jet A piston (yeah right) to enter the market?

TonyWilliams
06-22-2010, 12:53 PM
Yet you seem certain the solution is to just drop the lead and keep on going as though nothing happened because it works in some airplanes and one supplier in particular is pushing it? Care to enlighten us?


Not sure how you get that result. But, first, let me admit to one mistake in a previous post. The GAMI folks are promoting G100UL, not 94UL.

Their particular product, according to them, gets the job done technically. They have a full test cell for aircraft engines, and can run the tests as they did for AOPA recently at will. FAA asked them to have a full ATSM test done over about two years, as they asked of all their competitors.

At what cost per gallon for G100UL, I don't know. The rest is the same certification and economic debate, not technical.

As to 94UL, certainly that fuel, like mogas that is already approved in numerous airplanes, will work. Not technical. Not even legal if they just call it mogas with an STC that many planes already have.

Any of the above fuels, 94UL / G100UL / etc, would be better than 100LL for MOST airplanes. No more (or reduced) fouled plugs, less filth in the oil, etc.

As to the worst of the worst engines that need all the detonation help they can get... I don't know which might be worst, maybe a Lycoming in a Duke? A Rolls Royce in a P-51 Mustang? No, those airplanes will not be happy with something less than 100LL for the worst case scenarios (hot, high manifold pressure, carbon deposits that are heated in the combustion chamber, etc). Detonation will likely prevail. Heck, they probably would like 115 / 130 / 145 fuel !!!

What part of the fleet make up these turbocharged beasts? Each of them CAN be modified to operate without 100LL. Some of the fixes are quite simple. Lower manifold pressure. Some type of detonation monitoring. Lowered compression ratios. Not technical... economic and legal.

So, no, not saying every single plane can run UNMODIFIED on any fuel. I'm saying we should go to UL fuel as soon as possible, and that the limitations are not technical.

TonyWilliams
06-22-2010, 12:56 PM
The hardest part to reproduce is the block. And unlike auto clones, each aftermarket manufacturer would need FAA PMA approval.


I believe Superior makes (made?) their own Lycoming "block" (split cases). The other examples I used, Volkwagen and Chevrolet engines, are also COMPLETE engines, including an aftermarket block.

The Volkswagen clone is in a certified German sailplane, I think.

They are out there. It can, and has been done.

Edit: almost forgot the Porsche powered, and FAA certified, Mooneys

As I already stated, the defunk Thielert Mercedes Benz diesels, and the current Mercedes Benz diesels, all FAA certified.

Cubdriver
06-22-2010, 03:09 PM
Well ok, for all we know GAMI G100UL may be the winner in the future fuel sweepstakes. It does sound like a good candidate. I'll try an scare up some news on it and post it here.

TonyWilliams
06-22-2010, 04:58 PM
The first concern is the fuel producers. Last I recall, there was only one AvGas refinery (is this still true?) which constrains supply and vastly increases the price of an already expensive fuel.


I don't know how many refineries there are, or even how important that number is. It's small, we can all agree, I hope.

Once lead is removed, I suspect you will have MORE refineries wanting to sell a relatively high profit margin, boutique fuel that doesn't cause EPA concerns / shipping / storage problems.


A second concern is the technical viability of the 94 octane for EVERY engine. Cirrus is mentioned repeatedly, but what about the owners of C414 C421 and similar turbocharged pistons what would become worthless without massive modification? Many of these are still work horses for local economies.

Is their only remaining option to invest in a PT6 or hope for an inexpensive Jet A piston (yeah right) to enter the market?


Well, I think that you're adding drama to a straight forward process.

First, the 94UL doesn't obsolete anything. In a mostly unmodified engine, there would likely be a decrease in engine horsepower, through a VERY simple process of reducing manifold pressure. Maybe ignition gets retarded a degree or three. Don't know. But the sky won't fall, sorry. They already have low compression pistons because of turbocharging. Obviously, the more difficult issue would be compensating for the "higher" compression ratio engines, which are not pressurized cabin twin Cessnas.

Second, there are alternatives to Tetra Ethyl Lead (TEL). I think the GAMI folks are using a base stock petroleum fuel that is probably (if I were betting man) 94UL. Why reinvent the wheel? Then, maybe throw in a few non-TEL like one of the following????

Alternative antiknock agents

Antiknock agents (http://en.wikipedia.org/wiki/Antiknock_agent) are grouped into "high-percentage" additives, such as alcohol, and "low-percentage" additives based on heavy elements. Since the main problem with TEL is its lead content, many alternative additives that contain less poisonous metals have been examined. A manganese-carrying additive, methylcyclopentadienyl manganese tricarbonyl (http://en.wikipedia.org/wiki/Methylcyclopentadienyl_manganese_tricarbonyl) (MMT or methylcymantrene), is used as an antiknock agent in Canada[citation needed (http://en.wikipedia.org/wiki/Wikipedia:Citation_needed)], but its use as a fuel additive had been banned in the U.S. until 1995. Ferrocene (http://en.wikipedia.org/wiki/Ferrocene), an organometallic compound of iron (http://en.wikipedia.org/wiki/Iron), has also been reported as an effective antiknock agent.
Lead replacement additives were scientifically tested, and some were approved by the Federation of British Historic Vehicle Clubs, at the UK's Motor Industry Research Association (MIRA) in 1999.[14] (http://en.wikipedia.org/wiki/Tetra-ethyl_lead#cite_note-13)
High-percentage additives are organic compounds that do not contain metals, but they require much higher blending ratios, such as 20–30% for benzene and ethanol. It had also been established by 1921 that ethanol (http://en.wikipedia.org/wiki/Ethanol) was an effective antiknock agent, but TEL was introduced for mainly commercial reasons to replace it.[7] (http://en.wikipedia.org/wiki/Tetra-ethyl_lead#cite_note-Kitman-6) Oxygenates (http://en.wikipedia.org/wiki/Oxygenate), mainly methanol-derived MTBE (http://en.wikipedia.org/wiki/MTBE) and ethanol-derived ETBE (http://en.wikipedia.org/wiki/ETBE), have largely substituted the need for TEL. MTBE (http://en.wikipedia.org/wiki/MTBE) has environmental risks of its own and there are also bans on its use. ETBE, on the other hand, requires more expensive ethanol (http://en.wikipedia.org/wiki/Ethanol) as a starting material.
Improvements of the gasoline itself decrease the need for separate antiknock agents. Synthetic iso-octane (http://en.wikipedia.org/wiki/Iso-octane) and alkylate (http://en.wikipedia.org/wiki/Alkylate) are examples of such blending stocks. Benzene and other high-octane aromatics (http://en.wikipedia.org/wiki/Aromatic_hydrocarbon) can be also blended to raise the octane number, but they are disfavored today because of toxicity and carcinogenity.

TonyWilliams
06-22-2010, 05:26 PM
A couple of other thoughts:

My old Cessna 172 with the trusty O-320-E2D Lycoming was FAA certified to run on 80/87 fuel, and STC'd to run on car gas. It needs neither 100LL, or 94UL, or G100UL, or Space Shuttle gas.

My next plane, the Cessna 177, was certified for mid 90's octane gas. I'm confident that 94UL would work with no modifications.

I believe my O-470 Baron would also be ok completely unmodified (sorry, don't remember the actual certified octane number) The OI-520 Baron, maybe not, but then, I don't remember the actual number, because I always used the green 100/130, or blue 100LL.

Fuel-------Color-----Amount of lead per gallon

80/87-----Red--- ---0.5 mL
100LL-----Blue------1.2 - 2.0 mL
100/130--Green----3.0 - 4.0 mL
115/145--Purple----4.6 mL

rickair7777
06-22-2010, 06:18 PM
I believe Superior makes (made?) their own Lycoming "block" (split cases). The other examples I used, Volkwagen and Chevrolet engines, are also COMPLETE engines, including an aftermarket block.

The Volkswagen clone is in a certified German sailplane, I think.

They are out there. It can, and has been done.

Edit: almost forgot the Porsche powered, and FAA certified, Mooneys

As I already stated, the defunk Thielert Mercedes Benz diesels, and the current Mercedes Benz diesels, all FAA certified.

Oh, it can be done...the problem is that the aviation demand is not going to support the market

Aviation use of a converted auto engine is a risky endeavor, since any suitable engine is going to be modern and high-tech in order to meet the performance, weight, and reliability requirements of a broad-spectrum GA engine.

This means odds are very high that not every part part will be available aftermarket if the OEM shuts it down...and the odds of every part being PMA'ed? Astronomical, unless an aviation manufacturer adopted the engine and did all the leg work to ensure certification and sustained production/parts availability. This actually might be the best route, adoption vice clean-slate development.

The porsche thing was a lark, a marketing stunt.

VW engines don't count...that's the one engine that's been available since the 1930's in one form or another. It's suitable for a small homebuilt, but not for anything bigger. I can tear one down and rebuild it by the side of the road with a flashlight in my teeth, but I wouldn't trust most of them in an airplane. Msot of the current parts production is in latin america...

TonyWilliams
06-22-2010, 11:08 PM
an aviation manufacturer adopted the engine and did all the leg work to ensure certification and sustained production/parts availability. This actually might be the best route, adoption vice clean-slate development...


Exactly.

Here's a clean slate, Jet A burning, general aviation piston engine casting their own blocks!

DeltaHawk Diesel Engines (http://www.deltahawkengines.com/a_Casting.shtml)

TonyWilliams
06-22-2010, 11:33 PM
Maybe Cirrus will approve of this?

DeltaHawk Diesel-Powered SR20 Announced
Racine, WI – 08/07/2009 -- DeltaHawk Engines, Inc. and LoPresti Speed Merchants have begun work on a Supplemental Type Certificate (STC) to install a DeltaHawk Turbo-Diesel engine in a Cirrus SR20. The SR20 will be the first aircraft certified with the DeltaHawk engine.
The Jet-A fueled DeltaHawk Turbo-Diesel engine has the highest power-to-weight ratio of any aero-diesel engine. Its extraordinarily simple design provides high reliability and very low maintenance. On a typical mission it burns 30-40% less fuel than a gasoline engine, and it develops 100% of rated horsepower to 18,000 feet. When matched with the SR20 airframe, the package will offer higher payload and greatly enhanced range and speed. In addition, with Jet fuel available worldwide, the newly powered SR20 can be fueled anywhere in the world now and after 100LL is no longer available.
LoPresti Speed Merchants is known for making airplanes go fast. LoPresti’s expertise will offer a highly efficient and attractive cowl matched to DeltaHawk’s compact engine, bringing aerodynamic performance not available with a conventionally powered SR20.
“We are excited to be teamed with LoPresti for this project,” said Diane Doers, CEO of DeltaHawk. “The DeltaHawk-LoPresti collaboration is leading the way to the future of general aviation. The performance and value of the SR20 aircraft is going to be greatly enhanced. And this is just the first of many STCs that will be coming.”
“Our intention is to bring the DeltaHawk STC to market as fast as a bunny rabbit,” added Rj Siegel of LoPresti. “We are rabid fans of this engine and although it may seem that we have a wild hare up our butts, actually we just want to high tail it to market.”
Development work on the STC has been progressing for several months. SR20 Owners Tom Noonan and Steve Hart of Rochester, NY are providing their SR20 for the project, which is expected to be completed within a year.
DeltaHawk Engines brings “The Freedom to Fly ... Higher, Farther, Faster for less” to the General Aviation world.
About DeltaHawk:
DeltaHawk Engines, Inc., a Wisconsin corporation, is designing and building a family of direct drive liquid-cooled diesel cycle aviation engines from 100 to 650 hp. Four- cylinder engine models (160-200 hp) are in pre-production and higher horsepower models are in development. The engines are designed to use commercial jet fuels (Jet A, Jet A-1), military diesel fuels (JP-5, JP-8) or commercial diesel fuels (including biodiesel). Type Certification of the first model is expected in 2010. DeltaHawk’s innovative light-weight fuel-efficient engines, providing turbine-like reliability at a fraction of the cost, will lead to a “green” future for general aviation.
Contact:
Diane E. Doers, CEO 262-634-9660 DeltaHawk Diesel Engines (http://www.deltahawkengines.com)

Cubdriver
06-23-2010, 03:31 AM
Looks pretty good. Cessna had over a hundred orders for a Thielert diesel equipped C172 the latter went bankrupt due to poor management. The airplane had pretty good performance and did not cost a lot more. Word was it had a lag in the power response curve which threw the pilots who flew it off a little bit. They probably could have solved that problem and it is a shame the airplane was never put in production. If they had intended to try another diesel engine after that, a severe lack of funds for R&D in 2008 nixed the plan. Of course, replacing the GA fleet with Jet A burning aircraft is only a partial solution to the leaded-fuel problem- but every bit helps.

rickair7777
06-23-2010, 06:27 AM
The turbo/diesel lag should not be a big deal...turbjet drivers get used to longer lags. Add power to a 707 on short final and you'll have that power available by the time you reach the gate.

I assume dieselhawk is part 23 approved? With 160-200 HP that should cover the middle of the GA spectrum.

EDIT: OK looks like not certified yet but working on it. They are also working on larger engines. Hopefully this pans out, there are lots of advanttges to diesel (jet A).

Anybody know what auto engine it's based on? I poked around but couldn't find it. This is exciting, makes me want to start building my own airplane now...

TonyWilliams
06-23-2010, 07:27 AM
Anybody know what auto engine it's based on? I poked around but couldn't find it. This is exciting, makes me want to start building my own airplane now...


The Deltahawk is a 100% clean sheet design. They've been working on this for over a decade, but are nearing the actual certification. Manufacturer will be in MSP. STC's are in the works for many planes.

I'd like two of them for a Baron. 450hp ought to work :D

No Tetra Ethyl Lead... using existing aviation fuel (Jet-A, -A1, JP-5, etc) or diesel.... even kerosene in a pinch. Even "green" biofuels. No petroleum at all !!! Burns 30% less fuel per given horsepower than a petrol powered (100LL) machine. 100% hp to 18,000 feet (that ought to wake up your Cessna 172).

No valves, camshafts, rocker arms, valve springs.... the ONLY moving parts are the crankshaft, rods, pistons, oil pump, fuel pump, supercharger and turbocharger. It's direct drive, so no gear reduction like the certified Mercedes Benz engines. It requires no electricity to operate (although it does have electric start... why no air start option?).

It has been tested operating the crankshaft in either direction. The entire engine can be turned upside down, or vertical for helicopters.

Look at the pic below, and see how there's no cylinder head attachment.... they are cast as one. No bolts, threads, gaskets to blow out, nothing.

http://www.deltahawkengines.com/images/Engine-Glamour-0800shot02.jpg

TonyWilliams
06-23-2010, 08:18 AM
Politics in Fuel...

Quote from Cirrus dude in this thread:

Cirrus President "...let me be clear: Cirrus Aircraft does not believe that a 94UL solution is desirable for its owners or the health of the industry, and will strive for a better replacement fuel..."


And now the Cirrus engine manufacturer:

(7/27/09) Teledyne Continental Motors President Rhett Ross seems single-handedly determined to showcase how committed his company is to getting the lead out of avgas. As a demonstration of that commitment, Ross flew a turbocharged Cirrus SR22 from the company headquarters in Mobile, Ala., to EAA AirVenture in Oshkosh, Wis., at FL240 burning only UL94 avgas. UL94 is basically 100LL avgas without the lead component. With ASTM actively working the certification of UL94, TCM has shifted from testing the fuel to preparing its engines for its eventual introduction. Ross claims that bymid-2010, TCM will have equipped its entire product line of engines to run on unleaded fuel.

TonyWilliams
06-23-2010, 08:22 AM
Oh, just thought of another certified auto engine... the Toyota V-8. I believe the rating was 350hp.

Cubdriver
06-24-2010, 03:47 PM
DeltaHawk is an interesting engine design. We will probably see more of them. But you have to realize a major GA manufacturer always wants control over any part assembly they must have in order to make their airplanes. They will carefully avoid single-source suppliers for major assemblies. As long as there is a choice of some kind well ok, but as soon as only one engine works they tend to back off until they can either buy the STC from the original manufacturer or just buy the company that makes the engine. Cessna and Lycoming are allies under Textron, for example. When Cessna tried to buy the STC for putting Frank Thielert's 160hp turbodiesel into a Skyhawk and Thielert demurred on the deal, Cessna slowed development on the project to a crawl. The diesel Skyhawk was begun in the early 2000s and was barely done by 2008 when it was dropped. They were not happy about a single source engine supplier.

Tony, those two stories don't quite jibe do they? TCM and Cirrus seem to clash on whether Conti's will work without the normal octane rating. Curious disagreement there.

-----------------

Groups Ask for More Comment Time on EPA Avgas ANPRM

(Flying Magazine eNewsletter, 6/24/10) A group calling itself the Avgas Stakeholder Group has asked the Environmental Protection Agency to extend the comment period on its Advanced Notice of Proposed Rulemaking an additional 120 days. Originally scheduled for comments to close on June 28, the ANPRM addresses lead content in aviation fuels, and the implications of removing that lead are huge. Flying Editor in Chief Mac McClellan addressed the issue in his Left Seat column last week. AOPA president Craig Fuller calls it, "… one of the most complicated tasks our industry has ever faced." And Cirrus CEO Brent Wouters (who chairs an industry working group) points out that the issue is far from new, but that the EPA's Advanced Notice of Proposed Rulemaking has launched a regulatory decision-making process that could have major implications. At issue is how to get the lead out of 100 Low Lead aviation fuel. AOPA estimates that simply removing the lead (and reducing the octane rating) of current aviation fuel would have no affect on 70% of the GA aircraft in the fleet. But operators of the larger engines that need the higher octane to make their rated power fly proportionately higher numbers of hours, and tend to be aircraft used for charter, business flying and other missions that could be interpreted as more economically vital than those flown by operators of lower-power aircraft. In addition to AOPA, the Avgas Stakeholders Group includes: the American Petroleum Institute; the Experimental Aircraft Association, General Aviation Manufacturers Association, National Air Transportation Association, National Business Aviation Association and the National Petrochemical and Refiners Association.

CrimsonEclipse
06-25-2010, 11:52 AM
I'm curious about vibration on the DeltaHawk.

Mounted inverted would give great visibility and a smaller cowling would likely ad 5 kts.

A quick glance would assume an upright mounting on twin Cessnas and Beeches.

Now all you have to do is have locking fuel caps and monitor every fueling to prevent a Jet A/100LL/100UL mix up. You just KNOW it will happen.

Another question is if the turbo and super charger will actually make it to 2000 TBO. Will it require a 2 minute spin down like the 421/414?

TonyWilliams
06-26-2010, 07:55 AM
I'm curious about vibration on the DeltaHawk.


It's a 4 cylinder (and soon to be 6 and 8 cylinder) two cycle engine. It fires twice as often as a four stroke (virtually every other piston airplane engine except ultralight). I'm going to guess it will have far lower vibration than a 4 cylinder Lyc.


Now all you have to do is have locking fuel caps and monitor every fueling to prevent a Jet A/100LL/100UL mix up. You just KNOW it will happen.


It already has happened many, many times. One plane was fueled with Jet A when the line boy saw that it said "turbocharged" on the cowling. When asked how he got the big Jet nozzle in the small gasoline opening, he said that he had to go very slowly to get it filled up ! Plane crashed.

Cessna 441 and 421.... plenty of screw ups there. Aero Commanders (didn't Bob Hoover once get Jet A in his piston plane?)


Another question is if the turbo and super charger will actually make it to 2000 TBO. Will it require a 2 minute spin down like the 421/414?


It's a liquid cooled engine. Based on the pics, the turbocharger is not liquid cooled (Turbonetics on the turbo casting is a southern California company that sells turbochargers for performance cars). So, will probably require a cool down, like any metal tool that operates at 1650F, and is then exposed to something significantly less. So, who knows. Even if it doesn't require a two minute cool down, the FAA might require it.

Turbochargers are VERY simple. The only moving parts are the impeller wheels and the common shaft they are mounted to, and the bearings. So, what fails? The bearings. Why? Look at that filthy oil those bearings are exposed to. Imagine if a clean burning engine with no TEL (not exactly a trait of diesel engines) was using state of the art synthetic motor oil to lubricate those bearings?

The other turbocharger failures are junk going through the impellers. With no valves to break off and get ejected through the turbo, and with a good air cleaner on the intake side, and a good clean oil, I think the turbo has a greater chance than with an air cooled, carbon deposited, soiled dinosaur oil engine.

The supercharger will probably not go to TBO based on the belt drive. That will probably need to be replaced (with a prop removal $$$$$). Also, not crazy about the same belt running the alternator, because now a seized alternator will take out the supercharger. Also, no current room for a belt driven air compressor for a/c.

Cubdriver
06-27-2010, 06:44 AM
When I started this thread a year or two ago I thought it would go very slow, and it did for a while. The news clips often had months between them. The subject of which fuel or equipment is going to replace 100LL is heating up now though, and the pace has gone to about 5 articles a week from various sources. So, to keep this thread from being inundated by news clips I am reading all of them and only clipping those which say something important. The following story does not say anything terribly important, but it indicates some of the parties who are involved in the decision to make the change. FAA and EPA are probably going to make a deadline for the change in the next year. An ANPRM (advanced notice of proposed rule making) has already been issued. We are going to see some answer to the issue of discontinuing 100LL avgas pretty soon.

AOPA and GAMA talk with clubs about avgas solution

(AOPA 6/25/10 (http://www.aopa.org/advocacy/articles/2010/100621avgas.html)) Now is the time to be looking at all avgas alternatives—not ruling any out—AOPA and the General Aviation Manufacturers Association explained to a coalition of type clubs representing aircraft with high-compression engines during a meeting in Dayton, Ohio, on June 19. AOPA President Craig Fuller, along with Rob Hackman, AOPA vice president of regulatory affairs, and Walter Desrosier, GAMA vice president of engineering and maintenance, met with the owners’ groups to discuss the issue. Prompted by the anticipated Environmental Protection Agency mandate to reduce or remove lead from aviation gasoline, the type clubs, including American Bonanza Society, the Cirrus Owners and Pilots Association, the Malibu/Mirage Owners and Pilots Association, the Mooney Aircraft Pilots Association, and the Twin Cessna Flyers, are worried about a possible transition to a lower octane fuel replacement that could reduce their aircraft engines’ performance...

rickair7777
06-27-2010, 07:57 AM
It already has happened many, many times. One plane was fueled with Jet A when the line boy saw that it said "turbocharged" on the cowling. When asked how he got the big Jet nozzle in the small gasoline opening, he said that he had to go very slowly to get it filled up ! Plane crashed.



That was a turbo aztec, they use to have a "Turbo" decal as part of the trim...the aftermath resulted in an AD to remove the decal to prevent confusion.

Cubdriver
07-02-2010, 01:33 PM
Diamond DA42 NG flies on biofuel

(AOPA Online 7/01/10 T.A. Horne (http://www.aopa.org/aircraft/articles/2010/100629biofuel.html?WT.mc_id=100702epilot&WT.mc_sect=gan)) Diamond Aircraft Industries and the European Aeronautic Defense and Space (EADS) have teamed to fly a Diamond DA42 NG on algae-derived biofuel. The DA42 NG, which is equipped with a pair of Jet-A-burning Austro Engine AE300 engines, was recently flown at the ILA 2010 airshow in Berlin using the new fuel. The result, Diamond and EADS say, was performance equal to that experienced using Jet-A fuel—but a reduction in fuel burn of approximately 1.5 liters (about 1.6 quarts) per hour. Only minor modifications and adjustments had to be made to the DA42’s engines in order for the airplane to use the biofuel during the demonstration flights. EADS, even though it is not directly involved in fuel production, has been pursuing research for a suitable alternative to fossil fuels...

Diesel owners offered an upgrade

(AOPA Online, 6/01/10, A.K. Marsh (http://www.aopa.org/aircraft/articles/2010/100629centurion.html?WT.mc_id=100702epilot&WT.mc_sect=gan)) If you already own a Centurion diesel (jet fuel) 1.7 piston engine and want to upgrade to the 2.0, Centurion Aircraft Engines has a deal for you. Owners can get money back for unused flight hours if they upgrade to the next-generation Centurion 2.0 by Aug. 31. After receiving a supplemental type certificate for the installation of 155-hp Centurion 2.0s engines in the Cessna 172, the company launched this current campaign, the upgrade program for pilots with Centurion 1.7 engines. All types of aircraft with Centurion 1.7 engines can be equipped with the Centurion 2.0 engine. This applies to Cessna 172, Piper PA28, Robin DR400, and Diamond DA40 and DA42 aircraft. Since the Centurion 2.0 delivers 135 horsepower and has the same weight and size dimensions at the Centurion 1.7, it has the same supplemental type certificate...

Comment: Sounds good. But who owns one of these?

Firsthand look at one potential 100LL replacement

(AOPA ePilot, 7/08/10 (http://www.aopa.org/advocacy/articles/2010/100708avgas.html?WT.mc_id=100709epilot&WT.mc_sect=adv)) AOPA President Craig Fuller and senior members of the association’s government affairs staff traveled to Ada, Okla., July 7 for a demonstration of one of the possible solutions in the search for an unleaded aviation gasoline. Joining them at General Aviation Modifications, Inc. (GAMI) was Cessna Aircraft Company President and CEO Jack Pelton. “The dilemma of how to remove lead from avgas without affecting safety of flight has vexed our industry for years,” said Fuller. “So it is important that AOPA, as part of a general aviation avgas coalition, look at all potential solutions. That’s why we’re at GAMI again—to get an update on how their work on a fuel alternative is progressing.” (Learn more about GAMI's fuel, G100UL, in "Look, Ma, no lead.") AOPA and the other members of the coalition—the American Petroleum Institute (API), the Experimental Aircraft Association (EAA), the General Aviation Manufacturers Association (GAMA), the National Air Transportation Association (NATA), the National Business Aviation Association (NBAA), and the National Petrochemical and Refiners Association (NPRA)—are working closely with the Environmental Protection Agency and the FAA to develop and implement a comprehensive process for evaluating all aspects of potential solutions, from refining to actual performance in aircraft engines...

SomedayRJ
07-04-2010, 08:29 AM
I seem to remember John Deakin (who has forgotten more about octane, detonation, and so forth, than most of us dumb throttle pushers will ever know) writing a column at AvWeb about leaded aviation fuel; here it is: Lead in the Hogwash (http://www.avweb.com/news/pelican/182149-1.html). In short: Captain Deakin argues for 95NL. (Mind you, this is from 2002. I'm sure that things have changed a little since then.)

(As an aside: From a safety perspective (and as someone who used to pump aviation fuel...) I firmly believe that ONE and precisely ONE aviation fuel should be used in aviation reciprocating engines. Nightmares enough about misfueling with two types of fuel on the airport...)

To me, the constant bellyaching about lead in aviation fuel is a lot like the bellyaching ('discussion and implementation' if you prefer) about NextGen: we've been hearing about it for n > 20 years, and it's not ready yet. (That said, I would consider its extinction to be relatively imminent; for whatever reason, apparently now is the time?)

I currently operate an airplane that is type certificated for 80/87, 100LL or 100/130. No modifications on timing are required (as I recall: I don't switch fuels, since the only fuel I can by here in California is 100LL) for the engines to develop rated takeoff/METO power, although I would want to consult my maintenance manual and a familiar A&P before switching fuels out of habit. If you're curious, the engines in question are Lycoming GO-480-F1A6s, 275HP.

The other turbocharger failures are junk going through the impellers. With no valves to break off and get ejected through the turbo, and with a good air cleaner on the intake side, and a good clean oil, I think the turbo has a greater chance than with an air cooled, carbon deposited, soiled dinosaur oil engine.

This. :cool: I'm reminded of the colloquialism for the PRT on the R-3350 Turbo Compound fitted to the Lockheed Constellation: "Parts Recovery Turbine".

The supercharger will probably not go to TBO based on the belt drive. That will probably need to be replaced (with a prop removal $$$$$). Also, not crazy about the same belt running the alternator, because now a seized alternator will take out the supercharger. Also, no current room for a belt driven air compressor for a/c.

I'm not enamored with that...and I wonder what the FAA will think.

TonyWilliams
07-06-2010, 11:28 PM
I seem to remember John Deakin (who has forgotten more about octane, detonation, and so forth, than most of us dumb throttle pushers will ever know) writing a column at AvWeb about leaded aviation fuel


He had a stroke a year or two ago, and is done flying now. Awesome guy.

Hopefully, he'll get back to writing.

SomedayRJ
07-07-2010, 09:47 AM
He had a stroke a year or two ago, and is done flying now. Awesome guy.

Hopefully, he'll get back to writing.

Hope so :(

Cubdriver
07-14-2010, 02:56 PM
Senate GA Caucus co-chair speaks out on avgas

(AOPA ePublishing (http://www.aopa.org/advocacy/articles/2010/100713begich.html?WT.mc_id=ebrief), 07/14/10) A premature regulation of lead emissions from aviation fuel could have negative effects on the piston general aviation fleet across the nation. But GA-dependent communities in Alaska especially have a lot at stake, Senate General Aviation Caucus Co-Chair Mark Begich (D-Alaska) told the Environmental Protection Agency July 8. The impacts of a phaseout of lead from avgas would be magnified in Alaska, Begich wrote in a letter (http://download.aopa.org/epilot/2010/100713begich.pdf) to EPA Administrator Lisa Jackson. Begich explained the potential impact of regulations on avgas, called for the FAA to invest resources in developing an unleaded alternative to 100LL, and asked the agency for an additional extension to the comment period on an advance notice of proposed rulemaking so that Alaskans would have more time to review the document and comment.“The EPA should not phase out or eliminate 100LL until a suitable replacement is found,” Begich wrote. “A suitable substitute fuel should be affordable and should not require costly or impractical engine or airframe modifications to the in-use piston engine fleet.” (see story online)

Avgas lead producer allays supply concerns

The only producer of tetraethyl lead for avgas this month reaffirmed its commitment to continue to manufacture and supply the additive for the aviation industry. The Environmental Protection Agency took an early regulatory step this spring that could ultimately result in emissions standards mandating general aviation’s transition to unleaded avgas. The step has prompted some concerns that lead producer Innospec might stop production of tetraethyl lead before the industry is ready to transition to an unleaded fuel; the company issued an information update to allay those concerns...

TonyWilliams
07-14-2010, 09:29 PM
I love it.... only when the EPA stirs the pot a bit do the folks react. Otherwise, they'd be just happy as could be with leaded gas.

The same was true of cars when the government introduced CAFE fuel mileage numbers, and 5 mph bumpers, seat belts, and just about anything else. The sky was always falling.

And then it didn't.

CrimsonEclipse
07-15-2010, 03:31 AM
EPA: There, no more lead for cars. Avgas, you're next, better come up with an alternative.

Aviation: (*twiddles thumbs for 20 years*)

EPA: ok, no more lead in Avgas

Aviation: ZOMG!! WE NEED MORE TIME!!!!

SomedayRJ
07-17-2010, 08:48 PM
EPA: There, no more lead for cars. Avgas, you're next, better come up with an alternative.

Aviation: (*twiddles thumbs for 20 years*)

EPA: ok, no more lead in Avgas

Aviation: ZOMG!! WE NEED MORE TIME!!!!

"I didn't do my homework!"

Cubdriver
08-03-2010, 04:03 AM
LAMA Supporting Ethanol-Free Gasoline.

Flightglobal.com (http://mailview.custombriefings.com/mailview.aspx?m=2010073001aiaa&r=2974686-01c3&l=011-7e6&t=c) (7/29, Croft) reported, "The Light Aircraft Manufacturers Association (LAMA) is promoting an industry programme to create a premium ethanol-free gasoline for the general aviation community. Called 'eZero', the programme is designed to create sources for ethanol-free gas at airports."

Durban company [ADEPT Airmotive] flies high on biofuel

[Note: this is a repeat from May of this year, but I thought it deserved repeating]

(5/17/10, Sapa (http://www.timeslive.co.za/scitech/article454031.ece/Durban-company-flies-high-on-biofuel)) A Durban company has unveiled a light aircraft engine which can operate on biofuel or liquid petroleum gas. “Our technology benchmarks South Africa against the finest aviation engineering in the world,” said Andre Schoeman, chairman of ADEPT Airmotive, the company that developed the engine. The liquid-cooled engine, with advanced electronic engine management, was launched at Virginia Airport in Durban. It was fitted to a South African designed SA Ravin 500 light aircraft. The department of science and technology invested R10.5 million to fund ADEPT Airmotive to a pre-production stage. “Through investment in local research and development, it is fair to say that ADEPT is providing the catalyst for a genuinely world class general aviation manufacturing industry,” said Schoeman. He said the engine produced 320 horsepower, and boasted the lowest lead, nitrous oxide and carbon dioxide emissions and noise levels. United Kingdom based AgustaWestland Helicopters also provided financial support to ADEPT's certification process through the European Aviation and Safety Agency.

http://i284.photobucket.com/albums/ll8/Techman8/apc%20photos/adept.jpg

Will no-lead avgas cost $10 a gallon?

(8/17, A.K. Marsh, AOPA Pilot (http://blog.aopa.org/blog/?p=1350&WT.mc_id=100820epilot&WT.mc_sect=gan)) I debated awhile before posting this due to an obvious conflict of interest between the author of DieselAir newsletter who just wrote about the future of avgas, and his past consulting work. Andre R. Teissier-duCros was a consultant to an Atlanta company called DieselAir Aircraft formed to equip Cessna 182 aircraft with the SMA line of diesel engines, but the company no longer exists, according to former CEO Leonard Harris. Teissier-duCros is also publisher of the DieselAir newsletter. That said, I checked his background and decided his expertise is worth considering. The bottom line of his survey is this: a lead-free, ethanol-free alternative to 100LL will be available in five to eight years, but it will cost $10 a gallon. That price, the prediction goes, dramatically reduces the general aviation fleet. Manufacturers will begin equipping piston-engine aircraft with diesel engines–especially for fleet sales to flight schools. Many aircraft owners will switch to mogas, and the light sport aircraft equipped with Rotax engines actually prefer mogas. Those that can afford the $10-per-gallon price will continue to fly with the more expensive but environmentally friendly fuel, but will eventually convert to diesel engines when one is available for their make and model. Is that the truth, or a dream found in a PowerPoint presentation on the floor of the SMA board room? Teissier-duCros says it comes from his worldwide survey of opinion...

Cubdriver
08-23-2010, 11:25 AM
FAA Tests 100LL Alternative

(8/23, Bill Garvey, Aviationweek) (http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=busav&id=news/awx/2010/08/19/awx_08_19_2010_p0-249750.xml&headline=FAA%20Tests%20100LL%20Alternative) FAA has conducted another round of tests on an alternative fuel to leaded avgas, a new fuel which the developers said today is not only cleaner, but delivers more energy.The fuel, produced by Swift Enterprises Ltd., is made of pure hydrocarbons and can be derived from biomass, natural gas or even oil, according to Swift co-founder Mary-Louise Rusek, and is thus both renewable and sustainable. She said the FAA testing in a Lycoming IO-540 and other piston engines had demonstrated the fuel has an octane equivalent of 102. General aviation engine and airframe manufacturers have expressed a keen interest in the new Swift fuel, among others, since it promises to obviate the need for the tetra-ethyl-lead added to avgas to prevent knocking in high-performance piston engines. The general aviation fleet of light aircraft is now the nation’s largest consumer of leaded fuel, an unwelcome distinction. Swift is in discussion with outside firms about the possibility of producing the new fuel commercially.

Tests Show Alternative [Swift] Fuel Delivers 102 Octane 100LL.

(8/26, Flying eNewsletter) Last week, FAA tests demonstrated that a 100 low lead (100LL) alternative from Swift Enterprises can deliver the equivalent of 102 octane. The fuel is made of pure hydrocarbons and can be manufactured using biomass, natural gas or petroleum raw materials, making the new fuel substitute both clean and sustainable. According to Swift co-founder Louise Rusek, the FAA tested the Swift fuel in a Lycoming IO-540K, among other piston engines, and it developed the 100-plus octane rating that higher-power engines need to operate without knocking. The tests did reveal that the 300-hp Lycoming had no problems starting when hot, but was more reluctant to light off when cold. Other proposed 100LL replacements have shown octane ratings of up to 94 — sufficient for a large percentage of the piston engines in the general aviation fleet. But owners and operators of aircraft with higher power engines (that could operate at 94 octane only at reduced power settings) have protested, maintaining that their aircraft fly more hours than lower-horsepower models. They contend that any replacement for 100LL must serve the entire GA fleet, and that the FAA must take a leadership role in deciding on the imminent replacement fuel.

TonyWilliams
08-23-2010, 01:54 PM
The general aviation fleet of light aircraft is now the nation’s largest consumer of leaded fuel, an unwelcome distinction.




The only consumer ???

Cubdriver
08-23-2010, 02:54 PM
The only consumer ???

I don't know of any other consumption segment that still uses leaded gas. All the other segments have been through numerous evolutions and hence have left lead behind since the no-lead law began in the mid 70's.

Cubdriver
10-21-2010, 12:21 PM
FAA’s Hughes Center Adds Piper Twin for Fuel Testing

(D. Namowitz, AOPA Online (http://www.aopa.org/advocacy/articles/2010/101020hughes.html?WT.mc_id=ebrief) 10/21) Properties of avgas formulas are evaluated using ASTM International's standard test procedures in this laboratory at the FAA's William J. Hughes Technical Center. When the FAA’s NextGen Alternative Aviation Fuels Program, led by Dave Atwood, FAA program manager for fuels research at the William J. Hughes Technical Center (http://www.aopa.org/aircraft/articles/2008/081223fuels.html), examines how unleaded fuel formulas measure up to the performance of 100LL, much of the testing takes place in the center’s New Jersey laboratories. But you also need in-flight data, and that’s Armando Gaetano’s department. He manages the FAA’s R&D flight test program. When Atwood’s team completes the test-cell-based testing regimen for the avgas substitutes under development in the private sector, it will be Gaetano’s task to prepare the test aircraft, plan flight testing, and gather the data. Then it will be Atwood’s team who studies and summarizes the test data, reaches conclusions, and writes the reports. These reports will serve as reference for FAA certification officials as they evaluate fuels that may have significantly different composition and performance from today’s avgas...

Cubdriver
11-12-2010, 05:55 AM
Cessna, Bye Energy commit to electric Cessna 172.

[Ed note: so far, this thread has focused solely on biofuels for GA because they are certain to arrive at some point as 100LL avgas becomes obsolete. However, there seems to be a serious attempt to bring a Cessna Skyhawk equipped with batteries and an electric motor to the market. As long as the effort appears to be vigorous, I will cover news on that as well. It only has a range of about 90 minutes on a charge, but what the heck. Maybe they should just dump the electric bit and make it into a biofuel-powered turboprop.:)]

(ePilot (http://www.aopa.org/summit/news/2010/101111cessnabye.html?WT.mc_id=101112epilot&WT.mc_sect=summit), 11/12) "At a press conference at AOPA Aviation Summit, Cessna and Bye Energy announced significant progress on a joint project to retrofit Cessna 172s with 210-horsepower electric powerplants. Though it’s being called a technology demonstrator, the two companies sounded very much committed to bringing their “Green Flight Project” airplane to the market. For example, the first demonstrator’s schedule has the airplane making its first flight in the spring of 2011. The airplane will be powered by an electric motor manufactured by Bye Energy, and an optional, 40-hp Jet A-powered auxiliary power unit. The first airplane will have a two-blade composite propeller, but plans are to make a switch to a six-blade propeller on the first supplemental type certificated variants. Charles Johnson, COO of Bye Energy, said that the first electric Cessna 172s would match the performance of conventional, piston-powered 172s, and that its weight and balance profiles would not change “one bit.” He also said that gross weight would be the “same or lower” than a conventional Skyhawk. Of particular interest is the fact that the electric motor will not fall off with altitude—because it does not require air to generate power..."

SkyHigh
11-12-2010, 06:14 AM
It sounds awesome !! An electric 172 with an APU. I want one !!

Skyhigh

CrimsonEclipse
11-12-2010, 06:43 AM
Point of interest:
Cooling will be a concern with thinning air, like generators for certain turbines.

Cubdriver
11-12-2010, 07:05 AM
I'll have to admit my skepticism this project will get very far unless something revolutionary happens in the meantime. The energy content of liquid fuels is unmatchable short of nuclear fission. Either the costs will run high for the final product as it has for electric surface vehicles offering a standard driving range, or the range will be short as it is now and the prices will still be high due to the tiny production numbers involved. No free lunch. I envision a $350,000 Skyhawk with an operating range of 2 hours cruise with only 90 minutes usable and a 24-hour recharge cycle. The only hope for this thing is a breakthrough in battery technology, and while batteries are better than ever before they are still not able to pack the energy to weight of liquid fuel. An APU is almost comical on an airplane of this type and size, I predict that idea gets dropped within the first design cycle.

flywithjohn
11-12-2010, 07:51 AM
I have always heard rumors about 100UL or a synthetic 100LL, what I am worried about is the T-6 and Stearmen I have both where made to run 130 and what is going to happen when I can't even get Low Led?

TonyWilliams
11-12-2010, 08:48 AM
An APU is almost comical on an airplane of this type and size, I predict that idea gets dropped within the first design cycle.


Ya, that's just dumb. If they want a turbine, sure, but bolt a prop on it and eliminate the electric motor. Or vice versa.

clipperskipper
11-13-2010, 11:24 AM
I think the diesel like the Delta Hawk is the way to go, and it appears more cost effective over the life of the engine than it's gasoline counterpart.

Cubdriver
11-26-2010, 06:25 AM
I think the diesel like the Delta Hawk is the way to go, and it appears more cost effective over the life of the engine than it's gasoline counterpart.

I tend to agree that gasoline should be phased out in favor of diesel engines such as the DeltaHawk. Better aviation diesels are slowly being developed by firms that realize there are efficiency gains to be had through in high-pressure combustion that cannot be had with lower pressures. Perhaps they also want to offer a solution to the issue of oil dependence from natural reserves located in foreign lands which is a big issue to consider. There is also the possibility of an eventual depletion of natural reserves although the latter is not certain. In the meantime there must be a renewable non-leaded gasoline substitute for existing engines when 100LL is banned due to environmental rules. Clean turbo-diesel is a wonderful technology whose time has come in my opinion. The main barriers are high upfront investment figures and the slow sales of engines of this size. Here is a new aviation turbodiesel to add the the list:

500 hp [Raikhlin] diesel tested in Germany

(AOPA ePilot (http://www.aopa.org/aircraft/articles/2010/101122diesel.html?WT.mc_id=101126epilot&WT.mc_sect=gan), 11/26, A.K. Marsh) "Raikhlin Aircraft Engine Developments (RED), a new venture founded by Wladimir Raikhlin and his associates, has flown a 500-horsepower diesel engine on a modified Yak 52. The propeller for the water-cooled, twelve-cylinder engine called RED A03 is gear driven. It was built by RED Aircraft GmbH in Adenau, Germany. The engine generates 500 hp for takeoff at 3,900 rpm. The engine weight at the moment is 705 pounds, according to diesel engine consultant Andre Teissier-duCros. The company brochure does not give the weight, marking that specification as “to be announced.” The weight includes two alternators, a starter, an engine/gearbox oil heat exchanger, and a prop governor..."


Thielert [maker of biofuel-compatible GA turbodiesels]: Profitable, Seeking Investors.

(AvWeb (http://www.avweb.com/avwebflash/news/Thielert_Profitable_Seeking_Investors_203718-1.html), P. Bertorelli, 11/30) "Thielert Aircraft Engines GmbH says it has returned to profitability, improved its engines and is now seeking investors to continue its revival... After its initial reorganization in 2008, Thielert’s attempt to find investors yielded no results because of the global financial crisis. Further, the company’s sales dipped as Diamond Aircraft, the principle civil buyer of its engines, turned to its own engine supplier, Austro, to provide engines for the popular DA42 light twin. Thielert has a significant military market in supplying engine for UAVs... As of last September, said Thielert, 3000 of its engines were operating worldwide, making it the most successful aircraft diesel in history. The lifetime of the Centurion 2.0 engine was recently increased to 1500 hours and clutch and gearbox lifespans were extended to 600 hours. Although the gearbox and clutch lifespans still fall short of what Thielert promised two years after the engine was introduced, the company now claims net operating costs and efficiency are better than ever..."

Cubdriver
02-04-2011, 05:27 AM
Seems like this topic has slowed back down lately, but here is something.

Committee to advise on avgas transition

(AOPA (http://www.aopa.org/advocacy/articles/2011/110203committee_to_establish_unleaded_avgas_evalua tion.html?WT.mc_id=110204epilot&WT.mc_sect=adv), 02/04/11) FAA Administrator Randy Babbitt has signed a charter establishing an aviation rulemaking committee (ARC) (http://download.aopa.org/advocacy/110203unleadedavgascharter.pdf) to advise the agency on the move toward an unleaded fuel.The ARC will be a joint government/industry committee tasked with identifying key issues relating to, and providing recommendations for, the development and deployment of an unleaded avgas. The move comes in response to a request by the General Aviation (GA) Avgas Coalition, which includes AOPA, the American Petroleum Institute (API), the Experimental Aircraft Association (EAA), the General Aviation Manufacturers Association (GAMA), the National Air Transportation Association (NATA), the National Business Aviation Association (NBAA), and the National Petrochemical and Refiners Association (NPRA). “This is a much needed step in the process that will ultimately determine how the aviation industry reaches an unleaded fuel solution,” said Rob Hackman, AOPA vice president of regulatory affairs and liaison to the GA Avgas Coalition. “While the move toward an unleaded aviation fuel has been spurred by an Environmental Protection Agency action, it is the FAA that must approve new fuels, ensuring they provide adequate safety...


Avgas Alternatives

(S.Ells, 2/15/2011, Flying (http://www.flyingmag.com/aircraft/modifications-maintenance/avgas-alternatives)) In April 2010, the Environmental Protection Agency released an announcement that it was proposing to gather data to determine if leaded avgas is an environmental health hazard. The announcement in the form of an advanced notice of proposed rule making (ANPRM) has created reactions that range from a willingness to move forward in the search for the new lead-free avgas to alarm at the idea of government mandated changes and outrage due to what some see as a misguided plan to replace one boutique fuel with another. Regardless, the ANPRM served as a wake-up call to GA that 100LL is on the way out and the aviation community needs to figure out what to do next. Responders to the ANPRM questioned whether the tiny amount of lead in the GA fuel supply, which accounts for one-10th of 1 percent of the transportation fuel used in the country each year, presents a credible threat to health. Some bemoaned that scant attention was being paid to the fact that supplies of ethanol-free premium auto gas — a viable and FAA-approved fuel for more than 150 piston-powered airplane types and approximately 70 percent of the airplanes plying the skies — are rapidly shrinking due to congressional mandates to increase ethanol usage, a state of affairs that actually required more pilots to use 100LL instead of a viable unleaded auto-gas alternative...

A New G.A. Engine From Austro

(AvWeb (http://www.avweb.com/avwebflash/news/ANewGAEngineFromAustro_204201-1.html), 03/03/11, M. Grady) Austro Engine, best known for its work supplying powerplants for Diamond airplanes, announced this week it plans to develop a new 280-hp six-cylinder diesel engine for the general aviation market. Austro will work in partnership with Steyr Motors to develop the engine, based on the Steyr Monoblock Motor M1. That engine features an integral crankcase and cylinder head that has proven robust in marine and special-vehicle applications around the world, according to the company. The new engine is intended to power two Diamond aircraft now in the works: the DA50 Magnum, a single-engine five-seat airplane, and the twin-engine Future Small Aircraft (FSA) intended for personal and utility applications...

Cubdriver
03-04-2011, 07:43 AM
Diamond getting [Austro] 280-hp jet-fuel engine
New aircraft in the works

(AOPA (http://www.aopa.org/aircraft/articles/2011/110302diamond_getting_280_hp_jet_engine.html?WT.mc _id=110304epilot&WT.mc_sect=gan), 3/04, A. K. Marsh) Two of Austria’s key engine development companies, Austro Engine and Steyr Motors, signed a cooperation agreement to develop a 280-hp, six-cylinder aircraft engine. It will be used on two new Diamond Aircraft airplanes. Austro Engine (http://www.austroengine.at/?changelang=2) is developing the engine for the DA50 Magnum (single- engine, five-seat aircraft) and the FSA (Future Small Aircraft) twin-engine private and utility aircraft. Development, certification and production of these programs will take place at Diamond’s Wiener Neustadt facility in Austria...

TonyWilliams
03-04-2011, 08:21 AM
Here's their 250hp 6 cylinder. So, I'm guessing that they hook two of these together in a V-12 for the 500hp version.

http://www.steyr-motors.com/products/images/256.pdf

threeighteen
03-04-2011, 07:33 PM
Some bemoaned that scant attention was being paid to the fact that supplies of ethanol-free premium auto gas — a viable and FAA-approved fuel for more than 150 piston-powered airplane types and approximately 70 percent of the airplanes plying the skies — are rapidly shrinking due to congressional mandates to increase ethanol usage, a state of affairs that actually required more pilots to use 100LL instead of a viable unleaded auto-gas alternative...

This is what bothers me a lot. Ethanol is completely pointless for cars (worse fuel economy, takes more energy to make than it produces, uses valuable food resources, and drives up the cost/gallon), and now it's hurting the aircraft industry as well.

Cubdriver
03-25-2011, 05:12 AM
House R&D bill would continue unleaded-fuel research

(AOPA Online, 3/26/11) The House Science, Space, and Technology Committee has sent to the full House a bill containing language to authorize FAA research on an unleaded aviation fuel. The bill reauthorizing FAA research and development calls for continuing R&D activities “into the qualification of an unleaded aviation fuel and safe transition to this fuel for the fleet of piston engine aircraft.” It would require the FAA administrator to develop a plan for carrying out the policy within 120 days of the bill’s passage.
(http://www.aopa.org/advocacy/articles/2011/110318house_r_and_d_bill_continues_unleaded_resear ch.html?WT.mc_id=110325epilot&WT.mc_sect=adv)

Avgas research funding support urged

(D. Namowitz, AOPA, 5/23) A $2 million FAA budget request for research into an alternative to leaded avgas is an “absolutely critical part of the process” of switching the general aviation fleet to a lead-free fuel. That’s the message leaders of five GA associations sent in a letter urging members of a House committee to support the funding.The May 17 letter from the presidents of the GA associations urged members on the Appropriations Committee’s transportation subcommittee to support the funding proposal in the FAA’s fiscal 2012 budget. The funds would support research on the safety of different avgas formulations and development of airworthiness standards for engine modifications at the FAA’s William J. Hughes Technical Center in New Jersey. “This is an absolutely critical part of the process to identify and transition the general aviation piston fleet to a new unleaded avgas..."

Cubdriver
10-28-2011, 03:52 AM
Unleaded Swift fuel tested in radial engine

(S. Brown, AOPA (http://www.aopa.org/aircraft/articles/2011/111027unleaded_fuel_test_radial_engine.html?WT.mc_ id=111028epilot&WT.mc_sect=gan), 10/26) An unmodified Pratt & Whitney R-2800 Double Wasp engine running on Swift Enterprises’ high-octane unleaded fuel 100SF showed no signs of knock in an informal round of testing, Purdue Research Park announced Oct. 25. High-powered radial engines, designed to run on 115/145-octane fuel, present a significant challenge to any developer of an unleaded fuel. These engines already must run on reduced power settings on today’s lower-octane 100LL, and losing the knock protection provided by lead could further shrink their operating margins. The testing was part of an effort to prove that the fuel can meet the needs of engines that demand high-octane fuel, like the radial-engine aircraft that play an especially critical role in transporting people and supplies in Alaska—a question that Swift Vice President of Renewable Fuels Jon Ziulkowski said frequently arises during meetings with industry. “Everybody says, ‘Yeah, but will it work in a radial engine?’” he said. Now, the company can say, "Yes," he added. “It turns out it’s at least as good as 100LL."..

JamesNoBrakes
11-14-2011, 07:58 PM
I've flown the austro diesel quite a bit now, and it is impressive how little fuel they burn, but there is a HUGE problem with diesel...

For every barrel of crude, you can TWICE as much petrol as diesel. And actually, it's supposedly 20g of petrol, 10g of diesel, and 4g of jet-fuel. So while it's nice that diesels are more efficient, the fuel has more energy, and so on, it's always going to be more expensive and you can't run everything on it, far from it...

I remember the article lycoming gave to AOPA about how you really have to use 100 octane leaded fuel, and while some alternatives might work some of the time, you just can't get these fuels certified and have them run nicely with all the engines. When you read the article harder, it just seems like it's lycomings 1920s technology that's really holding them back. We really need to see some better engine designs, smaller displacement turbo engines. Auto engines have improved dramatically IMO, to the point where it just makes aviation technology laughable.

100, 110, 115 octane...seriously? This is why the diesel engines are a huge step forward. They are simply new technology. Something designed IAC with modern engines, high pressure fuel rails for atomization, direct injection, etc.

Lycoming and others need to invest in new technology. Of course, the problem is "it won't fit into a bonanza/cirrus" and all that, but seriously, something has to change.

I've always thought we have a unique nich with aviation, as there seems to be a whole lot more planes still in the air from 50 years ago compared to cars on the road from 50 years ago. At some point someone has to pay the price to keep an airplane going (you could easily argue that they already do, many times over). No one likes the idea of replacing an engine, but I think that's just what's needed; suitable replacements that can burn regular automotive fuel. Think about how much we pay for avgas in the first place, $5/gal, 6, how much more? 2000hr tbo x 8gph average x 5.5$/gal=$88,000 2000 x 7(more efficient engine) x 3.5=49000, that's a $39,000 difference...that's huge. I just don't see any viable solution that can be mass produced for a reasonable amount of money that will meet the needs of these outdated (but still perfectly functional) engines.

At the very least, we need to seriously consider significant modifications IMO.

TonyWilliams
11-14-2011, 10:10 PM
I've flown the austro diesel quite a bit now, and it is impressive how little fuel they burn, but there is a HUGE problem with diesel...

You know that diesel and jet fuel aren't that far apart, right? If there were no demand for petrol (gasoline), then they wouldn't make it.

I'm not sure what you're proposing, but there are bunches of planes using dinosaur Lycoming and Continental engines, that are burning regular car gas. I was burning car gas (with a legal STC) in my 1974 Cessna 172M with Lycoming O-320-E2D over 20 years ago. Nothing new.

Higher compression and turbocharged engines need more octane. That's just a fact. Any fuel that replaces what those engines were certified for would require modifications or power reductions, or both.

My utopia would be all airplanes would burn one fuel; jet A / diesel. Then, when jet fuel replacements become price acceptable (or we run out of cheap oil), then all planes would switch over to that synthetic oil replacement.



Product
Gallons per barrel
gasoline
19.5
distillate fuel oil
(Includes both home heating oil and diesel fuel)
9.2
kerosene-type jet fuel
4.1
residual fuel oil
(Heavy oils used as fuels in industry, marine transportation and for electric power generation)
2.3
liquefied refinery gasses
1.9
still gas
1.9
coke
1.8
asphalt and road oil
1.3
petrochemical feedstocks
1.2
lubricants
0.5
kerosene
0.2
other
0.3
Figures are based on 1995 average yields for U.S. refineries. One barrel contains 42 gallons of crude oil. The total volume of products made is 2.2 gallons greater than the original 42 gallons of crude oil. This represents "processing gain."

JamesNoBrakes
11-15-2011, 07:43 PM
You know that diesel and jet fuel aren't that far apart, right? If there were no demand for petrol (gasoline), then they wouldn't make it.

I'm not sure what you're proposing, but there are bunches of planes using dinosaur Lycoming and Continental engines, that are burning regular car gas. I was burning car gas (with a legal STC) in my 1974 Cessna 172M with Lycoming O-320-E2D over 20 years ago. Nothing new.

Higher compression and turbocharged engines need more octane. That's just a fact. Any fuel that replaces what those engines were certified for would require modifications or power reductions, or both.
Higher compression engines do not need high octane...anymore. Look at GMs direct injection 3.6. They are making 300hp and more without using high octane fuel. 326hp and 87 octane. There are more examples. The point is that automotive technology has continued to evolve relatively, and airplane engine technology stopped..way back in the beginning of the century.

What you say used to be true, until automotive timing and control got good enough. Turbocharged engines will probably always need some higher octane, but there was a multitude of reasons that lycoming listed why you can't just go and put 91 octane in a lycoming and run it. The real dissapointing part IMO is that they have not been designing to overcome this the entire time, rather they want the fuel designed for their engine.

What I'm proposing mostly is that the engine manufacturers stop producing these archaic designs and put some money into designing something somewhat modern that you can use 87, 89 or 91 octane pump gas in. Not that you can go and put 94 octane in it and get "ok performance", but that the engine is designed to run on those lower octanes from the get-go. For all those "old engines" out there, I think modifications (ignition systems rather than lawnmower magnetos) and fuel system upgrades are realistic solutions. It just seems like "designing the fuel for the engine" is always going to be a losing battle, there won't be but a few refiners making it, it will be very expensive due to the scale of production, and so on. I realize that to some extent this might have to happen for a few of the warbirds so they can perform at shows, but otherwise I just don't see any realistic to 100LL.

TonyWilliams
11-15-2011, 08:39 PM
I had to look up that General Motors engine:

The LLT engine has a compression ratio of 11.4:1, and has been certified by the SAE to produce 302 horsepower (225 kW) at 6300 rpm and 272 lb·ft (369 N·m) of torque at 5200 rpm on regular unleaded (87 octane) gasoline.

Yes, that truly is a high compression engine, although I've had 12 and 13:1 engines on my motorcycles for a couple decades. With a carburetor!

Anyway, news flash; Lycoming isn't going to leave their bread and butter of grossly overpriced engines that you HAVE TO BUY if you have an airplane with one, since that's what it's certified for, and the cost to develop something new cannot be spread out over the relatively small fleets.

I been at Oshkosh many times to see the latest engine developments, and while there are many in the experimental machines, certified machines are a different breed. I've seen the Toyota (V-8 certified in the Malibu and Navajo) attempts, Honda (with Continental), and other big name players who know HOW to make an engine. None are available in the market for many, many good reasons (that aren't technical).

So, perhaps a new plane with a new engine is possible, but I sure hope it doesn't burn petrol !!! The best one I've seen that may have a chance is:

DeltaHawk Diesel Engines (http://www.deltahawkengines.com/)

Grumble
11-15-2011, 10:07 PM
When an automobile engine can run at 75-90% for several thousand hours efficiently, without fail.... I'll put one in my airplane. Oh and it cant weigh more than the IO-360 I have in there now. The homebuilt crowd has been having this argument for decades and attempt after attempt has been made, with no real success for a reason. It dosent work. Only recently has electronic ignition and adjustable timing started to make it's way into the scene reliably. Mazda rotary engines are probably the closest thing to an answer, but no one has been able to crack the code on a reliable reduction drive unit. And running mogas above 8.5:1 is just fine as long as you run very very rich. Start leaning and your detonation margin is almost nil. Never mind the ethanol debacle.

If there is an answer, it's diesel. Someday.

Cubdriver
11-16-2011, 03:01 AM
Lycoming and Continental are working on newer technologies to allow the new engines to run on any fuel, but the problem remains they are going to sell 4 of them, and while monopoly makes them drag feet somewhat the real issue is the small numbers of production- no matter what engine they produce. I do not see either company as a callous bullies with a strangle hold on piston aviation, more like a hobby industry that has a zero R&D budget. That plus the steep cost of certification testing for all airplane powerplants leads to the archaic state we have now. In addition to those blocks the other one is the incredible lifespan of the typical piston airplane. Where else can you find engines sitting around that are older than you are. Those engines have to be fueled, and they cannot realistically be retired as long as they run safely on 100 octane. It's going to take a drop in non-leaded replacement gasoline, plus a metric ton of years for all those high octane engines to be out of the picture.

JamesNoBrakes
11-16-2011, 06:25 PM
I had to look up that General Motors engine:

The LLT engine has a compression ratio of 11.4:1, and has been certified by the SAE to produce 302 horsepower (225 kW) at 6300 rpm and 272 lb·ft (369 N·m) of torque at 5200 rpm on regular unleaded (87 octane) gasoline.

Yes, that truly is a high compression engine, although I've had 12 and 13:1 engines on my motorcycles for a couple decades. With a carburetor!

Anyway, news flash; Lycoming isn't going to leave their bread and butter of grossly overpriced engines that you HAVE TO BUY if you have an airplane with one, since that's what it's certified for, and the cost to develop something new cannot be spread out over the relatively small fleets.

I been at Oshkosh many times to see the latest engine developments, and while there are many in the experimental machines, certified machines are a different breed. I've seen the Toyota (V-8 certified in the Malibu and Navajo) attempts, Honda (with Continental), and other big name players who know HOW to make an engine. None are available in the market for many, many good reasons (that aren't technical).

So, perhaps a new plane with a new engine is possible, but I sure hope it doesn't burn petrol !!! The best one I've seen that may have a chance is:

DeltaHawk Diesel Engines (http://www.deltahawkengines.com/)

I know lycoming isn't going to do it on their own, it's going to take something like the deltahawk being successful, and then lycoming/continental will try to "catch up" with a modern design, but the real question is if they'll fall flat on their face or pay for their lack of foresight.

That engine BTW makes 323hp in the 2012 camaro now, as it's been updated a little from the original spec that showed up in the CTS, impressive, but I had to go for the V8 version :) Yes, the V8 engine is 200lbs heavier than a IO-360, but it's making more than twice the power of one, and they are being used in light aircraft. There are others in the same catagory, and I think the basic principle is that automotive technology has advanced, and has been designed around the available fuel, rather than the other way around.

I think the only real constant in business is change, and that it's key to any successful company. The minute you start complaining about competitor A being able to do something for less, offer a cheaper or more popular product, you are falling into the rut of not being competative and failing to innovate. The idea of being able to make a wiget on a production line unchanged with the same machines and people will never work. This is my main gripe with "made in america" crusaders, because competition is necessary and it's when businesses do not evolve that they die. They need to invest in new processes, equipment, people, designs, new markets, new products, and so on. If you "sit on your heels", someone is going to smoke you. If lycoming and continental do not innovate and bring about the necessary change, they deserve all that is comming to them, and to die out. It's when the government steps in and props-up failing business and bad business models that the entire industry get dragged down and everyone suffers (see Airline Industry :D ).

I'm planning on building an RV-7...and diesel would probably be my first choice, there are some other decent alternatives too. It's getting there...

threeighteen
11-24-2011, 10:14 PM
I'm planning on building an RV-7...and diesel would probably be my first choice, there are some other decent alternatives too. It's getting there...

I'm after an RV10 with a deltahawk. winning strategy imho.

Cubdriver
06-29-2012, 06:38 AM
Pain at the Pump-What the transition from 100LL avgas to unleaded aviation fuel could mean for you.

(Flying (http://www.flyingmag.com/blogs/fly-wire/avgas-pain-pump?cmpid=enews062812&spPodID=030&spMailingID=5401675&spUserID=NDc4NjI0MjIwMAS2&spJobID=201656201&spReportId=MjAxNjU2MjAxS0), S. Pope, 6/28/2012) Dissecting the just-released final report submitted by the FAA’s Unleaded Avgas Transition Aviation Rulemaking Committee (UAT ARC), here’s what you need to know about the future of 100LL avgas:

• There’s no real financial motive for any of the major fuel suppliers to create an alternative to 100LL aviation gasoline because the market is so small.
• No approved alternatives to 100LL currently exist, and coming up with one that can replace leaded avgas without requiring changes to aircraft systems might be impractical.
• The EPA doesn’t really care about these last two points, and is insisting that leaded aviation fuel be banished from production.
• The FAA’s experts think it will take 11 years, or maybe longer, to make the transition to an alternative fuel. As a result, the agency is launching a government-industry initiative called PAFI (Piston Aviation Fuel Initiative) to figure it all out.
• Nobody knows what an alternative fuel will cost at the pump – even more worrying, there is a risk that 100LL could become an extremely scarce fuel before the transition to an alternative is completed.

Reading between the lines of the UAT ARC’s report, I see few reasons why an acceptable alternative to 100LL avgas can’t be identified and approved. The key is timing. Some small companies have already come up with innovative solutions, with the major barrier preventing one or more of these fuels from entering mainstream production being the FAA’s own unwillingness to test and certify them. Of course, with the creation of the PAFI, that process can begin...

chrisreedrules
06-30-2012, 10:41 AM
What about a bigger version of the rotax like they use in the Tecnam twins and a few others? They have pretty awesome performance and use MOGAS.

hindsight2020
06-30-2012, 04:27 PM
You can run ethanol-laden mogas on lycos and contis too, the obstacles are not science based, it's all FAA red tape. The concern about ethanol eating away at materials just shows the GA fleet needs to get with the program. That is why I can't wait to go experimental, where none of the old wives tales of ethanol-blended mogas matter one iota. Then I can legally haul the stuff from the pump down the street to my airplane with automotive parts from the alternator on down to the brake lines and the fuel lines. Just don't fuel your airplane up and not fly it for 6 months. Your car wouldn't start either under the same circumstances...Screw 100LL.

I know I know, 10% of the GA market drives the demand for the other 90%, because that 10% of the fleet burns 90% of the gas. To that I say, let them have at it and release the rest of the fleet from the grips of 100LL by offering street mogas at the airport. Problem solved.

These spam cans are all going to the scrap yards when the boomers start losing their medicals en masse anyways. The economics of 8GPH per 100 knots and $20,000 1930s rebuilt tractor engines is economically outmoded for the current times.

Cubdriver
07-23-2012, 05:17 PM
Nice of you to stop in, Hindsight.
~~~~~~~~~~~~~~~~~~~~~~~~~~

"Game changer" now that's an original phrase. The new diesel Skylane will work with biofuel Jet-A in due course of time. It's nice they are selling them now so the few that sell depreciate by time the cost per gallon of "bio-A" becomes decent in 2020 or 30. I still can't believe a 182 runs half million bucks though. Maybe it mixes martinis.

~~~~~~~~~~~~~~~~~~~~~~~~~~

Cessna unveils "Turbo NXT" Skylane

(AOPA ePilot (http://www.aopa.org/oshkosh/2012/news/120723cessna-unveils-turbodiesel-182.html?WT.mc_id=120720epspec&WT.mc_sect=osh&cmp=ePlt:RdMr), 7/23/12, S, Brown) A Cessna 182 powered by a 230-horsepower Jet-A-burning piston engine will be available in the second quarter of 2013, Cessna Aircraft announced July 23. The thinly masked Turbo182 NXT on display at the Cessna exhibit at EAA AirVenture drew widespread attention even before the official start of the show and unveiling. Cessna’s Jeff Umscheid said the aircraft is a response to customer demand. “This is what the market has been begging for,” he said, calling the aircraft a game changer. Powered by a turbocharged, direct-drive SMA SR305-230E-C1 engine, the Turbo 182 NXT will burn 11 gph at a max cruise speed of 155 knots, Umscheid said, granting owners a lower fuel burn and increased range from avgas counterparts...

threeighteen
07-23-2012, 05:41 PM
Nice of you to stop in, Hindsight.
~~~~~~~~~~~~~~~~~~~~~~~~~~

"Game changer" now that's an original phrase. The new diesel Skylane will work with biofuel Jet-A in due course of time. It's nice they are selling them now so the few that sell depreciate by time the cost per gallon of "bio-A" becomes decent in 2020 or 30. I still can't believe a 182 runs half million bucks though. Maybe it mixes martinis.

~~~~~~~~~~~~~~~~~~~~~~~~~~

Cessna unveils "Turbo NXT" Skylane

(AOPA ePilot (http://www.aopa.org/oshkosh/2012/news/120723cessna-unveils-turbodiesel-182.html?WT.mc_id=120720epspec&WT.mc_sect=osh&cmp=ePlt:RdMr), 7/23/12, S, Brown) A Cessna 182 powered by a 230-horsepower Jet-A-burning piston engine will be available in the second quarter of 2013, Cessna Aircraft announced July 23. The thinly masked Turbo182 NXT on display at the Cessna exhibit at EAA AirVenture drew widespread attention even before the official start of the show and unveiling. Cessna’s Jeff Umscheid said the aircraft is a response to customer demand. “This is what the market has been begging for,” he said, calling the aircraft a game changer. Powered by a turbocharged, direct-drive SMA SR305-230E-C1 engine, the Turbo 182 NXT will burn 11 gph at a max cruise speed of 155 knots, Umscheid said, granting owners a lower fuel burn and increased range from avgas counterparts...

11 gph at 155 knots? Biofuel or not, that's not very efficient for a turbo diesel. 16 statute miles per gallon...

CrimsonEclipse
07-23-2012, 06:59 PM
:rolleyes:

Wow, General aviation is saved!!!

Now everyone can have a half million airplane to fly to work.

detpilot
07-24-2012, 03:22 AM
?11 gph at 155 knots? Biofuel or not, that's not very efficient for a turbo diesel. 16 statute miles per gallon...

Are you kidding? It's not amazing, but it is by no means inefficient. That's a comparable burn and speed to a cirrus sr-20. I challenge you to find a car that gets 16mpg at 177mph.

hindsight2020
07-24-2012, 04:43 PM
It's a turbo though, that thing will rip you apart come overhaul time. Who are we kidding, the thing is half a million bucks. GA is screwed.

JamesNoBrakes
07-24-2012, 09:14 PM
Like a 182RG, but just a bit slower!

155ktas isn't much of a problem for a NA 182RG, turbo 182 can do like 173 at 14gph, 162kts at 12gph...Twinstar with 14gph is doing better than 160kts...that's TWIN engine burn.

What disappoints me almost as much as the cost is the weight. A new 172 weighs as much (nearly 1800) as an old 182 RG....RG for gods sakes! I realize there are some improvements to crashworthiness, but with cars these improvements are usually incorporated while at the least not increasing weight, these things have become pigs...

I love cessnas, but you can't keep wrapping the same turd sandwich up in new clothes and making it less desirable. It's like one of those tricked out Caddys from the 80s. It pretty much starts to suck at EVERYTHING. While not the fastest, a good useful load and ruggedness offset this. Now it has a much lower useful load with less excess performance. Offer it in a more bare-bones lightweight package. Let the customers outfit it with the A/C, anti-ice, power seats, televisions, etc. They should NOT be trying to compete against SR20/22s and DA50s with 182s.

rickair7777
07-25-2012, 06:18 AM
11 gph at 155 knots? Biofuel or not, that's not very efficient for a turbo diesel. 16 statute miles per gallon...


If you can get an airplane in the ballpark of a passenger car, you are doing OK.

An airline ticket is break-even on fuel consumption vs. driving long distances as long as the plane is pretty fuel (they usually are) and the driver is sole occupant (often the case).

The airplane's a lot faster on a TRANSCON, but anywhere you can drive to in a day, you'll save a bunch of money by driving if you have a family of five.

SkyHigh
07-25-2012, 02:20 PM
In the mid-1970's my parents bought a nice home in the suburbs. I remember at the time that the purchase price was about the same as a Cessna 172 at the time. Decades later and the same home is now valued in the upper 300 to lower 400K range. About the same as a new Cessna 172 today.

The thing that is different is that we lost 18 years of plane production during the 1980's and 1990's. As such we have sticker shock since we have not had anything new to look at in recent memory. In addition GA is missing 18 years of used inventory to help bridge the gap.

All we have really is old 1970's junk and very new 2000 and up. It is kind of discouraging for the new generation who is not comfortable with older stuff like that.

Skyhigh

Cubdriver
07-27-2012, 03:46 PM
Looks like Conti is going to jump on the diesel bandwagon as well. Cessna uses mostly Lycos and Textron owns Lycoming, but the Columbia uses Continentals so it would be sort of cool if there were a turbodiesel Columbia available at some point.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Continental Motors unveils plans for trio of diesels

(D. Hirschman, AOPA (http://www.aopa.org/oshkosh/2012/news/120724continental-motors-unveils-plans-for-trio-of-diesels.html?WT.mc_id=120727epilot&WT.mc_sect=osh), 7/27/12) Continental Motors will obtain FAA certification this year on the first of what the company promises will be a full line of diesel aircraft engines ranging from 150 to 350 horsepower. "These kinds of commitments allow our customers and our suppliers to know and plan their activities," said Continental CEO Rhett Ross. "We will certify a (diesel engine) this year, and we will be in rate production in the first quarter of 2013. Continental hasn't announced any launch customers for the three sizes of diesel engines it plans to produce. (Cessna Aircraft chose an SMA diesel engine for the recently announced Turbo 182 NXT. Continental's first diesel engine will be a turbo-charged 200- to 250-hp model called the TD-300. The TD-450, a 300- to 350-hp version, will go into production in 2015; and a TD-220, a 160- to 180-hp version, will be produced beginning in 2017. The push into engines designed to burn kerosene-based fuels is driven by the lack of leaded avgas in some international markets and uncertainty about the future of 100LL in the United States, Ross said. At the same time, Continental is moving to address questions about the cost and availability of avgas by certifying low-compression piston engines to run on unleaded auto fuel—even auto fuel that contains ethanol. "We are not abandoning the higher horsepower engines," Ross said. "We fully desire a drop-in replacement for 100LL--but we're not going to wait for it."...

JamesNoBrakes
07-27-2012, 04:31 PM
Looks like Conti is going to jump on the diesel bandwagon as well. Cessna uses mostly Lycos and Textron owns Lycoming, but the Columbia uses Continentals so it would be sort of cool if there were a turbodiesel Columbia available at some point.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Continental Motors unveils plans for trio of diesels

(D. Hirschman, AOPA (http://www.aopa.org/oshkosh/2012/news/120724continental-motors-unveils-plans-for-trio-of-diesels.html?WT.mc_id=120727epilot&WT.mc_sect=osh), 7/27/12) Continental Motors will obtain FAA certification this year on the first of what the company promises will be a full line of diesel aircraft engines ranging from 150 to 350 horsepower. "These kinds of commitments allow our customers and our suppliers to know and plan their activities," said Continental CEO Rhett Ross. "We will certify a (diesel engine) this year, and we will be in rate production in the first quarter of 2013. Continental hasn't announced any launch customers for the three sizes of diesel engines it plans to produce. (Cessna Aircraft chose an SMA diesel engine for the recently announced Turbo 182 NXT. Continental's first diesel engine will be a turbo-charged 200- to 250-hp model called the TD-300. The TD-450, a 300- to 350-hp version, will go into production in 2015; and a TD-220, a 160- to 180-hp version, will be produced beginning in 2017. The push into engines designed to burn kerosene-based fuels is driven by the lack of leaded avgas in some international markets and uncertainty about the future of 100LL in the United States, Ross said. At the same time, Continental is moving to address questions about the cost and availability of avgas by certifying low-compression piston engines to run on unleaded auto fuel—even auto fuel that contains ethanol. "We are not abandoning the higher horsepower engines," Ross said. "We fully desire a drop-in replacement for 100LL--but we're not going to wait for it."...

Now THIS I agree with! It's time the large engine manufacturers embrace it.

threeighteen
07-30-2012, 12:31 PM
Neat! :)

threeighteen
08-11-2012, 09:43 AM
Are you kidding? It's not amazing, but it is by no means inefficient. That's a comparable burn and speed to a cirrus sr-20. I challenge you to find a car that gets 16mpg at 177mph.

With the right gearing, a car could easily get such mileage. My car gets 25mpg (US miles, US gallons) consistently at about 110 mph (on the autobahn). It's a 3.2L gas engine which makes about 320bhp, no turbo, seats 4 comfortably, and it has far from optimal gearing (80mph is almost 4,000 RPM!). A diesel with good gears could likely do much much better.

An RV10 with a deltahawk twincharged diesel engine (still waiting on certification :mad:) will do 193kts on 8.5 GPH, a 100LL Mooney can do 160kts on 10gph... Both will seat 4.

Both of those blow this "awesome super-efficient turbodiesel cessna" out of the water for less than 1/4 of the cost.

JamesNoBrakes
08-11-2012, 06:39 PM
Um, if you get 25mpg at 110mph, you must get about 100mpg at 55...right?

threeighteen
08-13-2012, 02:22 PM
Um, if you get 25mpg at 110mph, you must get about 100mpg at 55...right?

Negative, it's about 39-40.

detpilot
08-13-2012, 05:39 PM
With the right gearing, a car could easily get such mileage. My car gets 25mpg (US miles, US gallons) consistently at about 110 mph (on the autobahn). It's a 3.2L gas engine which makes about 320bhp, no turbo, seats 4 comfortably, and it has far from optimal gearing (80mph is almost 4,000 RPM!). A diesel with good gears could likely do much much better.

An RV10 with a deltahawk twincharged diesel engine (still waiting on certification :mad:) will do 193kts on 8.5 GPH, a 100LL Mooney can do 160kts on 10gph... Both will seat 4.

Both of those blow this "awesome super-efficient turbodiesel cessna" out of the water for less than 1/4 of the cost.

I'm skeptical of this "magical" car of yours, but in any event- at those speeds, hearing has little impact on your fuel burn. If your statement about your car's performance was true, better gearing doing the rpm down to 3000 rpm would have a very minor effect on mileage, if the engine could even maintain the load at that rpm. People overestimate the effect of gearing, especially at high speeds in automobiles.

Comparing a rv10 to a certified airplane is not fair, I guarantee the rv stall speed is greater than the 61 knots that the faa requires for certificated single engine pistons. That diesel rv is impressive, but unless regulations are relaxed, no certified airplanes will be able to compete on a speed per horsepower basis.

Cubdriver
08-15-2012, 05:57 PM
As Rick hinted a few posts ago, it's not fair comparing airplanes to ground vehicles because the latter are not after the same set of optimization goals. Cars will always win the efficiency game if going from point A to point B without using much energy is the goal, because they stay in ground effect and do not fight gravity in so doing.

threeighteen
08-16-2012, 05:47 PM
I'm skeptical of this "magical" car of yours, but in any event- at those speeds, gearing has little impact on your fuel burn. If your statement about your car's performance was true, better gearing doing the rpm down to 3000 rpm would have a very minor effect on mileage, if the engine could even maintain the load at that rpm. People overestimate the effect of gearing, especially at high speeds in automobiles.

Gearing has EVERYTHING to do with fuel burn in a car, and has an almost exponential effect on your fuel burn as speed increases.

When I raised my final drive ratio by .15 (a noticeable, but small change), fuel mileage at higher speeds dropped by about 7 mpg. Drag does play a significant factor, but gearing in a vehicle is much more of a factor than you account for.

I'm almost curious to see what would happen if I dropped my final drive down by .45, I might even have the proper unit in my garage, but it would rob my acceleration by a noticeable factor.

Comparing a rv10 to a certified airplane is not fair, I guarantee the rv stall speed is greater than the 61 knots that the faa requires for certificated single engine pistons. That diesel rv is impressive, but unless regulations are relaxed, no certified airplanes will be able to compete on a speed per horsepower basis.

RV10 published stall speed is 57 mph statute, which equates to under 50mph nautical. You could certify the RV10 yourself if you wanted, you'd just have to shell out the clams to buy a few kits and build them all the same way and then get a type certificate from the FAA.

As for airplanes vs cars, theres no doubt you can make cars more efficient. Several of the newer diesels are capable of more than 100mpg if driven properly, however airplanes can be made comparably efficient. Klaus Savier did a 1985 sm transcon in his two seater VariEze, using only 25.8 gallons, that's about 77mpg, he's been known to hit almost 100 mpg in competitions as well.

JamesNoBrakes
08-16-2012, 08:12 PM
Gearing has EVERYTHING to do with fuel burn in a car, and has an almost exponential effect on your fuel burn as speed increases.

When I raised my final drive ratio by .15 (a noticeable, but small change), fuel mileage at higher speeds dropped by about 7 mpg. Drag does play a significant factor, but gearing in a vehicle is much more of a factor than you account for.

I'm almost curious to see what would happen if I dropped my final drive down by .45, I might even have the proper unit in my garage, but it would rob my acceleration by a noticeable factor.



RV10 published stall speed is 57 mph statute, which equates to under 50mph nautical. You could certify the RV10 yourself if you wanted, you'd just have to shell out the clams to buy a few kits and build them all the same way and then get a type certificate from the FAA.

As for airplanes vs cars, theres no doubt you can make cars more efficient. Several of the newer diesels are capable of more than 100mpg if driven properly, however airplanes can be made comparably efficient. Klaus Savier did a 1985 sm transcon in his two seater VariEze, using only 25.8 gallons, that's about 77mpg, he's been known to hit almost 100 mpg in competitions as well.

I agree with everything here, just not the 25mpg at 110mph. I got 27mpg in my big V8 a few weeks back on a 750mi trip (one day), 26.6 the next day over 650mi the next day. People are usually amazed I can get that out of this brick of a car, but it's a combination of the 6th gear ratio and really knowing how to squeeze the mileage out (minimizing stops and starts, using the car's 1-4 gear skip shift feature, avoiding unnecessary accelerations, etc). It turns 1700rpm for about 70mph, and yes, that does make for decent mileage. On the flip side, I've owned a few "fast" cars now, any time you get to speeds like what you posted, you burn a TON of fuel, I also know people that own the same car that I do that can't figure out why they get more than 13-15mpg. I've gone fast in a big V8, a much smaller 4cyl turbo, and a few in between. When you "cruise" at those speeds, you can almost watch the fuel gauge move the entire time. If your gearing is such that you can cruise at 70mph at the rpms I listed, it can be difficult to accelerate to those speeds (in that gear). The drag going from 70, to 80, to 90, to 100 and then faster is huge. It's not linear, as we know, so it's not going to cost 2mpg for every 10mpg over 70, it has a huge effect at 110mph in a car.

Cubdriver
10-19-2012, 02:09 PM
You can drive any chemical reaction backwards if you throw enough energy at it in the form of heat and/or pressure. This new fuel therefore sounds like huge waste of electrical power, making a small amount amount of liquid fuel from a massive amount of input electricity. At best it sounds like a way to store energy in places where there is a lot of wind/water power and no way to get it to the grid.
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Scientists turn fresh air into petrol

(S. Connor, The Independent (http://www.independent.co.uk/news/uk/home-news/exclusive-pioneering-scientists-turn-fresh-air-into-petrol-in-massive-boost-in-fight-against-energy-crisis-8217382.html), 10/19/12) A small British company has produced the first "petrol from air" using a revolutionary technology that promises to solve the energy crisis as well as helping to curb global warming by removing carbon dioxide from the atmosphere. Air Fuel Synthesis in Stockton-on-Tees has produced five litres of petrol since August when it switched on a small refinery that manufactures gasoline from carbon dioxide and water vapour. The company hopes that within two years it will build a larger, commercial-scale plant capable of producing a ton of petrol a day. It also plans to produce green aviation fuel to make airline travel more carbon-neutral. Tim Fox, head of energy and the environment at the Institution of Mechanical Engineers in London, said: "It sounds too good to be true, but it is true. They are doing it and I've been up there myself and seen it. The innovation is that they have made it happen as a process. It's a small pilot plant capturing air and extracting CO2 from it based on well known principles. It uses well-known and well-established components but what is exciting is that they have put the whole thing together and shown that it can work." Although the process is still in the early developmental stages and needs to take electricity from the national grid to work, the company believes it will eventually be possible to use power from renewable sources such as wind farms or tidal barrages. "We've taken carbon dioxide from air and hydrogen from water and turned these elements into petrol," said Peter Harrison, the company's chief executive, who revealed the breakthrough at a conference at the Institution of Mechanical Engineers in London.

"There's nobody else doing it in this country or indeed overseas as far as we know. It looks and smells like petrol but it's a much cleaner and clearer product than petrol derived from fossil oil," Mr Harrison told The Independent. "We don't have any of the additives and nasty bits found in conventional petrol, and yet our fuel can be used in existing engines," he said. "It means that people could go on to a garage forecourt and put our product into their car without having to install batteries or adapt the vehicle for fuel cells or having hydrogen tanks fitted. It means that the existing infrastructure for transport can be used," Mr Harrison said. Being able to capture carbon dioxide from the air, and effectively remove the principal industrial greenhouse gas resulting from the burning of fossil fuels such as oil and coal, has been the holy grail of the emerging green economy. Using the extracted carbon dioxide to make petrol that can be stored, transported and used as fuel for existing engines takes the idea one step further. It could transform the environmental and economic landscape of Britain, Mr Harrison explained. "We are converting renewable electricity into a more versatile, useable and storable form of energy, namely liquid transport fuels. We think that by the end of 2014, provided we can get the funding going, we can be producing petrol using renewable energy and doing it on a commercial basis," he said. "We ought to be aiming for a refinery-scale operation within the next 15 years. The issue is making sure the UK is in a good place to be able to set up and establish all the manufacturing processes that this technology requires. You have the potential to change the economics of a country if you can make your own fuel," he said. The initial plan is to produce petrol that can be blended with conventional fuel, which would suit the high-performance fuels needed in motor sports.

The technology is also ideal for remote communities that have abundant sources of renewable electricity, such solar energy, wind turbines or wave energy, but little in the way of storing it, Mr Harrison said. "We're talking to a number of island communities around the world and other niche markets to help solve their energy problems. "You're in a market place where the only way is up for the price of fossil oil and at some point there will be a crossover where our fuel becomes cheaper," he said. Although the prototype system is designed to extract carbon dioxide from the air, this part of the process is still too inefficient to allow a commercial-scale operation. The company can and has used carbon dioxide extracted from air to make petrol, but it is also using industrial sources of carbon dioxide until it is able to improve the performance of "carbon capture". Other companies are working on ways of improving the technology of carbon capture, which is considered far too costly to be commercially viable as it costs up to £400 for capturing one ton of carbon dioxide. However, Professor Klaus Lackner of Columbia University in New York said that the high costs of any new technology always fall dramatically. "I bought my first CD in the 1980s and it cost $20 but now you can make one for less than 10 cents. The cost of a light bulb has fallen 7,000-fold during the past century," Professor Lackner said.

rickair7777
10-19-2012, 02:47 PM
The Navy is looking at a similar scheme to turn seawater into Jet-A.

But in their case it makes sense...available reactor power is unlimited (at least for 20 years or so) so Jet-A storage and at-sea resupply ends up being the limiting factor for sustained carrier flight ops.

JamesNoBrakes
10-19-2012, 06:00 PM
I read that story over dinner tonight...and made fun of it.

Cubdriver
10-26-2012, 05:06 PM
"I Was Sick of L.A. Traffic. So I Took a Plane to Work..."

(A. Jones, 10/25/12, LAWeekly Blogs (http://blogs.laweekly.com/arts/2012/10/traffic_commute_plane_cars_highway.php)) I am flying westward over the Angeles Crest Mountains, the morning sun shining down over the San Fernando Valley as it spreads out below me and we bank south. The Cessna 152, aptly named "the Commuter," cruises at just over 3,500 feet as we travel from the Agua Dulce Airpark toward Santa Monica Airport -- a 47-mile trip that will put me just two miles from my office in Culver City. Exhilaration rushes through me as the plane reaches optimal speed, or "trues out," at about 95 knots, the propeller spinning in a blur. The pilot, Michael Gold, checks in with air traffic control, effortlessly communicating a long string of flight information consisting of letters and numbers. I may be on my way to work, but this is definitely not an ordinary workday. I don't usually commute by small plane. Other than the Lakers' Kobe Bryant -- who famously helicopters from Newport Beach to Staples Center -- who does? Since I started my job a year ago, in fact, I've been commuting almost 70 miles round-trip each day on L.A.'s jam-packed streets, spending, on average, three hours (or more) stuck in traffic on the 405.Like so many Angelenos, I've become numb to the frustration of fighting the gridlock every morning at the dreaded interchange of the 101 and the 405. Mere mention of the words "Skirball" or "Getty Center" is enough to keep me in my office until well past 8 p.m. When it's just too much and I'm completely stopped on the highway, needing to pee so badly, my numbness turns to desperation: Screaming inside and crying proverbial tears of blood, I tell myself that there must be a better way! But the thought remained just that -- a cry for help more than a plan for action -- until I met Michael Gold.Gold is in his second year of flight training, working toward his commercial license. A recent college graduate and studio musician, he has been obsessed with airplanes since childhood. After our brief introduction at a friend's barbecue, it was only a few seconds before the conversation turned to traffic. I launched into my usual complaints, only to be stopped short when he casually mentioned that, by air, the same trip would take about nine minutes. Nine minutes? I couldn't believe what I was hearing.Was there really hope? A way around the traffic? Some sort of salvation? I had to try this! But could I really fly to work?...

Cubdriver
11-01-2012, 12:29 PM
Avgas Issues Will Take Time To Resolve
Aviation International News » November 2012

(M. Thurber, 11/01/12, AINOnline (http://www.ainonline.com/aviation-news/aviation-international-news/2012-11-01/avgas-issues-will-take-time-resolve)) The aviation industry is slowly headed toward development of an unleaded replacement fuel for avgas-burning piston-powered aircraft, and a recent move by the FAA is an encouraging sign that progress will continue. The FAA recently agreed to open a new Fuels Program Office, according to NATA, that will provide “technical expertise and strategic direction in the planning, management and coordination of activities related to aviation fuels.”

NATA and several other aviation associations (AOPA, EAA, GAMA and NBAA) sent a letter on August 1 to FAA acting administrator Michael Huerta, asking for the FAA’s help in funding and managing efforts to find a suitable replacement for 100LL (100-octane) avgas. 100LL relies on the additive tetraethyl lead to prevent detonation in high-compression piston engines that power high-performance aircraft, and pressure from environmental groups and the U.S. Environmental Protection Agency (EPA) has intensified scrutiny of leaded avgas.

An aviation rulemaking committee has explored the avgas issue and made recommendations to the FAA. According to the association letter to the FAA, “We are at a critical phase between consideration of the Unleaded Avgas Transition Aviation Rulemaking Committee (UAT ARC) recommendations and implementation of a fiscally responsible FAA unleaded avgas program that will achieve this objective.” The letter asked Huerta to fund the FAA’s avgas program with $5.5 million in the Fiscal Year 2014 budget, “not only for the economic sustainability of general aviation in the U.S., but also for its safety.”

The FAA avgas program will help in two key ways. One is to demonstrate that the FAA and industry are working together on a clear path to an unleaded fuel replacement. Without that clarity, owners, operators and investors won’t be motivated to maintain their aircraft and invest in new avionics and other aviation technologies. “An avgas program is also needed to support the FAA’s statutory role in cooperation with the EPA to implement any lead emissions standards for aircraft it deems necessary under the Clean Air Act,” according to the letter...

Cubdriver
01-16-2013, 08:02 AM
In my post #120 of this thread, I pasted a clip from AOPA about the new Cessna "Turbo NXT" Diesel Skylane, later renamed the JT-A. It is one of the first biofuel compatible GA aircraft and it evens burns Jet-A rather than Swift fuel, or another avgas biofuel. It's ungodly expensive to most people, but it is also a solid move forward in this area. Here's a followup clip (you gotta like "game changer", now that's an original phrase).

Cessna website- Skylane JT-A (http://www.cessna.com/single-engine/skylane-jta.html)
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Cessna Closing In On Certification For JT-A Skylane.

The Wichita (KS) Eagle (http://mailview.custombriefings.com/mailview.aspx?m=2013011601aiaa&r=2974686-e571&l=014-c7d&t=c) (1/16, McMillin) reports, "Cessna Aircraft is nearing certification of its four-seat 182 JT-A Skylane equipped with a diesel engine, which is designed to burn jet fuel." The article notes with the "uncertain future for low-lead aviation gasoline," or avgas, "worldwide, Cessna officials said the 182 JT-A - with its 230-horsepower engine - is poised to be an industry game-changer." Brian Cozine, an engineer specialist in advanced design at Cessna, stressed that not only does it use less fuel than avgas engines, but can fly longer distances as well. Currently, the company "is scheduled for Federal Aviation Administration certification by the end of March, with first delivery in the second quarter followed by certification from European authorities in the third quarter."

West Lafayette-based [avgas maker] Swift Fuels expands reach into Europe

(02/01/2013, H. Colombo, JCOnline (http://www.jconline.com/article/20130201/BUSINESS/302010037?gcheck=1&nclick_check=1)) The Purdue Research Park company that is working to develop a sustainable commercial replacement for aviation gasoline announced Friday that it has expanded its reach in Europe. Swift Fuels LLC has acquired 50 percent of German firm Swift Fuel GmbH, a move that will give it greater access to foreign investors. Swift Fuel GmbH was registered in January 2011 as a Swift Fuels subsidiary. The deal allows Swift Fuel GmbH the ability to license the intellectual property and technical expertise from the West Lafayette firm. “This is a major milestone in our efforts to broaden Swift Fuels’ market coverage and deepen our technical base,” said Swift Fuels chief executive officer Chris D’Acosta. D’Acosta would not release financial terms of the deal. The acquisition took place in Germany. “The strategy is to allow (Swift Fuel GmbH CEO) Thomas Albuzat and (civil engineer) Andreas Penner to serve as our partners in behalf of Swift Fuels LLC throughout Europe,” D’Acosta said via email. “They have contacts of potential investors. We thought our commitment to license our intellectual property and technical expertise (will) help position us with more European investors.”

Diesel Cessna JT-A on Track for Imminent Certification

(M. Phelps, Flying, 4/25/2013) With 13 airplanes on the production line, Cessna's jet-A-burning Turbo Skylane JT-A is on schedule for certification and first deliveries before the end of June. "We are on track," said Jeff Umscheid, business leader for the project. "We have been taking orders since [EAA AirVenture 2012 last summer]." The JT-A's SMA diesel engine is exhibiting a 40 percent increase in fuel efficiency, compared with gasoline engines, said Umscheid, and its electronic engine controls (with mechanical backup) and single power lever simplify the pilot's engine management chores. "The reduction in pilot workload is substantial," he said. An important goal of the program was to market a Skylane able to use more widely available jet fuel, because avgas is scarce in many parts of the world. And even where it is available, leaded avgas is costly to manufacture and deliver, since equipment used to make and deliver it cannot be used with unleaded auto fuels. Cessna also announced its composite TTx is preparing for first deliveries in May. The first flight of a production airplane was in March. With a cruise speed of 235 knots, the TTx is billed as the fastest certified single-engine fixed gear aircraft. Brian Steele, business leader for the TTx program, pointed out that speed isn't the only virtue of the new model.
Its Garmin 2000 avionics suite includes touch-screen panels. Touch-screen control pads, air conditioning, side sticks, golf-bag-friendly baggage space and stitched leather on the seats contribute to the overall value.

Cubdriver
05-24-2013, 06:36 AM
This sounds good, but will not work for all aviation piston engines so is not a final solution.
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Arizona Startup To Produce Unleaded Aviation Gasoline

(S. Pope, 05/23/13, Flying (http://www.flyingmag.com/news/arizona-startup-produce-unleaded-aviation-gasoline?cmpid=enews052313&spPodID=030&spMailingID=17550753&spUserID=NDc4NjI0MjIwMAS2&spJobID=216199848&spReportId=MjE2MTk5ODQ4S0)) An Arizona company called Airworthy AutoGas said it plans to start production of a high-purity, low-vapor-pressure 93 octane unleaded aviation gasoline this fall that could replace 100LL avgas in about 80 percent of piston airplanes. “A growing number of general aviation aircraft do not require 100LL avgas or a 100 octane unleaded drop-in replacement,” noted Mark Ellery, Airworthy’s director of business development. “That, coupled with the scarcity of suitable ethanol-free automotive gasoline in the marketplace, resulted in the development of Airworthy AutoGas.”

hindsight2020
05-24-2013, 07:17 PM
This sounds good, but will not work for all aviation piston engines so is not a final solution.



Well, it's called go turbine. The reason the recreational side of GA is dying is in part to having to spend twice as much for effectively what 87 UL can provide, only because 20% of the fleet that's not recreational is 80% of the 100LL market. They're holding recreational GA hostage. Even the ethanol concern is overstated. Of course in this litigious society, no one can be allowed to exercise the discretion of NOT parking the ol C-172 with two tankfuls of 87UL for six months then take it up for a spin with so much as sumping the tanks. That would be too much to ask, which is why the FAA doesn;t allow me to run ethanol blend, though when I run it in the experimental (and the certified...) it runs fine. And if your engine is normally aspirated you simply ain't gonna get too high for mogas vapor pressures to be an issue.

You want a resurgence in GA traffic? Make mogas widely available at the ramp where customers can get it...for $3.67. "Special 94UL" for $5.95 ain't gonna fix the problem either.

Cubdriver
05-25-2013, 05:47 AM
Agree 100%. Light GA needs mogas gas as of yesterday. Even the ethanol adulterated works ok in most of them. And non-ethanol gas is readily available. These airplanes do not fly well near their service ceiling so lowering it a little to cut the cost the fuel in half is only smart. I have learned that local resistance to installing mogas at local fields is more about the cost of the tanks and installation than anything else- airport operators look at moving 200 gallons a week for ten grand and that's the end of it. The solution may be to develop a program that allows dual use fuel pads- cars and light trucks over here, GA over there, same tanks pumps and gas for all.

threeighteen
05-25-2013, 10:09 PM
The solution may be to develop a program that allows dual use fuel pads- cars and light trucks over here, GA over there, same tanks pumps and gas for all.

I'd be willing to fuel my car up at the airport to support this, probably would be putting better quality fuel in my car too.

CrimsonEclipse
06-02-2013, 08:40 AM
The solution may be to develop a program that allows dual use fuel pads- cars and light trucks over here, GA over there, same tanks pumps and gas for all.

That would be a tax problem. Not an insurmountable one, but still a BIG problem for law makers and people afraid of lawyers.

Cubdriver
06-11-2013, 12:34 PM
This isn't really news, but it gives something of a status report on the subject.
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FAA wants unleaded airplane fuel

(A. Halsey III, Washington Post (http://www.washingtonpost.com/local/trafficandcommuting/faa-wants-unleaded-airplane-fuel/2013/06/10/bcbffe8e-d203-11e2-a73e-826d299ff459_story.html), 06/11/13) The Federal Aviation Administration wants some airplanes to run on the same thing cars have been using for years: cleaner burning unleaded fuel. The FAA said Monday that it will ask the fuel industry for proposals to develop a new unleaded fuel by 2018 for use by the non-commercial airplanes known as the general aviation fleet. “General aviation is vital to the U.S. economy and is an important form of transportation for many Americans,” Transportation Secretary Ray LaHood said in a statement. “We need to work with industry develop an unleaded fuel that advances aviation safety and improves the environment.” The unleaded fuel would replace the 100 octane low-lead formula now being used in about 167,000 general aviation planes in the country. The FAA said that fuel is the last of its type in use in the United States that adds tetraethyl lead to boost octane to the level needed for high-performance airplane engines. The formulas submitted by industry developers will be tested at the FAA’s laboratory near Atlantic City using $5.6 million included in the White House’s 2014 budget...

Embry-Riddle: GAMI G100UL Tests Looks Promising

(P. Bertorelli, 08/27/13, AvWeb (http://www.avweb.com/avwebflash/news/Embry-Riddle-GAMI-G100UL-Tests-Looks-Promising220495-1.html))Embry-Riddle Aeronautical University’s testing of GAMI’s G100UL unleaded fuel looks promising, the school told AVweb last week, and it says it sees no reason why the fuel can’t be a drop-in replacement for 100LL. With two major flight training campuses, ERAU wants an unleaded replacement for avgas sooner rather than later and has been testing both Swift Fuel and General Aviation Modifications Inc.’s G100UL in a school Cessna 172. “Our students are green aware and they’ve made it clear we want to go in the direction of eliminating leaded fuel. If we can get an unleaded fuel, we would like to get out of 100LL, no question. We’re footing the bill for what we’re doing in the testing,” said ERAU’s Pat Anderson, who’s overseeing the G100UL test program at the school’s Daytona Beach campus. ERAU’s test program is divided into three phases: a FAR Part 23 airframe certification test including climbs, shutdowns and restarts and a FAR 33 150-hour in-flight longer-term performance trial. Phase three will repeat the initial testing to identify any differences in findings. The test aircraft is a Cessna 172 with an engine at TBO, but with two new cylinders that will allow gauging wear that might not be evident on the run-out cylinders. Anderson expects the flight trials to be done by the end of the year with further testing, perhaps an operational pilot program, to follow...

Shell Unleaded Avgas: New formula 10 years in the making

(J. Moore, 12/03/2013, AOPA (http://www.aopa.org/News-and-Video/All-News/2013/December/3/shell-unleaded.aspx)) Shell has been working for a decade in a dedicated aviation laboratory developing an unleaded aviation fuel. Shell has been working for a decade in a dedicated aviation laboratory developing an unleaded aviation fuel. Shell Aviation, a subsidiary of the multinational oil giant Royal Dutch Shell, announced Dec. 3 that a 10-year effort in the laboratory has produced a fuel that may put a long-sought goal—once thought to be unattainable—within reach: a lead-free “performance drop-in” replacement for 100LL that could power any aircraft in the piston fleet. “That’s our definite goal,” said Michael Sargeant, avgas commercial aviation manager for Shell Aviation, in a phone interview, when asked specifically about the ambition to produce a “performance drop-in” avgas replacement. “We’ve tested it and had some exciting and successful tests.” The lead-free formulation has a motor octane number (MON) over 100, a critical factor in formulating a fleetwide fuel that could power high-compression engines. (Octane prevents premature ignition known as detonation, and is measured by more than one scale.) Shell’s new lead-free formula has passed preliminary tests in Lycoming engines on the ground, and a Piper Saratoga recently flew for about an hour on the fuel, according to a news release from Shell—the first of many tests that will be required for certification. “It’s an exciting milestone,” Sargeant said, adding that the company looks forward to working with manufacturers across the general aviation industry, and various regulatory agencies. The company will pursue fleetwide certification rather than a model-by-model approach. Sargeant said tests done on the new formula to date “indicate that it’s a great candidate for fleetwide approval.” The exact path that Shell must navigate to gain such approval remains to be established. The FAA has a goal of deploying a lead-free piston aviation fuel by 2018, though Sargeant said the company may be able to achieve required approvals and start distribution sooner than that. “We believe two to three years might be possible,” Sargeant said. “That’s the timeframe that we would love to work towards. The details need to be developed.” Sargeant said another design goal is to keep the retail price similar to avgas, though it is too early to know exactly what the new fuel would sell for. Shell has only just begun conversations with the various regulatory agencies involved. The fuel will be submitted for approval from the FAA, ASTM, and the European Aviation Safety Agency...

Cubdriver
01-31-2014, 04:49 AM
Unleaded Aviation Fuel Initiative Gets Funding Boost

(S. Pope, Flying (http://www.flyingmag.com/news/unleaded-aviation-fuel-initiative-gets-funding-boost#mbozSwbYp4QatdAi.99), 01/28/2014) The $1.1 trillion government spending bill passed by Congress includes money for the Piston Aviation Fuels Initiative (PAFI), an FAA plan to start the transition to high-octane unleaded piston aviation fuel by 2018. The appropriation for fuel research was slightly higher than the requested level through fiscal year 2014. PAFI is an FAA/industry partnership that will begin evaluating candidate fuels this summer. The program aims to replace 100 low lead avgas with unleaded gasoline that can be used in the vast majority of piston-powered general aviation airplanes. The 2014 budget includes nearly $6 million in research and development funding for the William J. Hughes Technical Center in Atlantic City, New Jersey, to conduct the fuels evaluation testing. "This is a crucial program for the health and long-term viability of general aviation," said Doug Macnair, vice president of government relations for the Experimental Aircraft Association. "Funding PAFI at the requested level keeps us on track for a managed, sustainable, and safe transition to a high-octane unleaded replacement for 100 low lead."

block30
02-01-2014, 04:26 PM
Thanks for the update, Cub. I am following this with a high degree of interest myself, as I still fly GA (when my wife lets me!) and because GA has so many economic impacts.

Cubdriver
07-11-2014, 09:52 AM
This topic slowed down a lot during the last two years, but apparently 9 distinct Avgas formulas have been identified as the final contestants in the rather slow race to find a 100LL Avgas replacement.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

FAA Receives Unleaded Fuel Proposals For General-Aviation Aircraft.

USA Today (http://mailview.bulletinmedia.com/mailview.aspx?m=2014071101aiaa&r=2974686-531f&l=010-d6f&t=c) (7/10, Jansen) reported that the FAA has announced that it received “10 proposals for unleaded fuel to consider for general-aviation aircraft.” USA Today said that the FAA will now “determine by Sept. 1 which fuels to send to an agency lab in Atlantic City for testing that Congress authorized $6 million for this year.” Transportation Secretary Anthony Foxx said, “We’re committed to getting harmful lead out of general-aviation fuel.” Pete Bunch, CEO of the General Aviation Manufacturers Association, called the effort “a key milestone for ensuring the continued safety of our aircraft, benefiting the environment and minimizing the economic disruption to our industry.”

Yoda2
07-11-2014, 01:02 PM
My fuel of choice is CH3NO2!

block30
08-04-2014, 11:13 AM
Avgas replacement: It?s not just about octane - AOPA (http://www.aopa.org/News-and-Video/All-News/2014/July/31/shell-talks-about-steps-toward-unleaded-avgas)

After testing more than 3,000 formulas over a 10-year period, Shell Aviation submitted its candidate fuel to the FAA for consideration as a fleet-wide, unleaded avgas replacement in July. Company officials at EAA AirVenture were optimistic about the Piston Aviation Fuels Initiative’s plan to have a replacement in place by 2018 but acknowledged that there are many challenges to overcome in the next four years.

What the FAA, fuel industry, and aviation industry are trying to do—certify an unleaded fuel that will work in all piston engines in the general aviation fleet and come as close to the specifications as leaded avgas as possible to minimize operational limitations—has never been done before.

“It’s never been done before, but everyone wants this to succeed,” said Michael Sargeant, Shell Aviation’s unleaded avgas commercial leader. “Everyone needs this to succeed.”

The FAA is currently reviewing nine candidate fuels submitted from five groups: Afton Chemical Company; Avgas LLC; Shell; Swift Fuels; and a consortium made up of BP, TOTAL, and Hjelmco. Shell Global Technical Manager of Aviation Fuels Robert Midgley said the FAA will be judging the fuel properties of each candidate against 21 specifications that are key to ensuring a fuel is safe for aircraft engines.

Of critical importance, Midgley said, is taking what has been learned from 90-plus years of experience flying with avgas, and making sure the new fuel is as close to the historical norm as possible. And, he explained, it’s more difficult than just removing the lead.

“It’s not that easy,” he said, adding that if had been easy, lead would have been removed from avgas 20 or 30 years ago. “It’s not just the octane,” he said, but the “other 20 specs are important.”

Midgley said that Shell’s fuel meets 19 of the 21 specifications and is close to meeting the remaining two: final boiling point and energy density. Shell has performed numerous engine bench tests with the fuel and flown with it in a Piper Saratoga. The company said will begin more extensive flight testing later this summer, but tests so far show that the fuel has the same detonation and performance characteristics as leaded avgas.

A path forward

Sargeant was quick to point out that Shell, or any other fuel supplier, can’t bring an unleaded product to market alone. “The key to bring any fuel to market,” he said, is a “collaborative space,” that includes testing support and historical data from engine and aircraft manufactures, aviation groups, and the FAA.

That’s where the PAFI steering group comes in. The group includes the FAA, AOPA and other aviation advocacy groups, and the American Petroleum Institute. Through PAFI the government and aviation and fuels industries will work to create tests for the fuels that will lead to data needed for the fleet-wide approval of the fuel or fuels with the least impact on the existing fleet.

“Without that PAFI process, it would be impossible to bring a fuel to market,” said Midgley. “It’s really turning the process 180 degrees.” Historically, the FAA has certified engines to run on certain fuels. But through this process, the FAA’s goal is to have a new fuel work in existing piston engines.

Since PAFI was created, Midgley said that he is starting to see the aviation industry switch gears and really step up to participate in the process—beyond the testing support Continental, Lycoming, and some aircraft manufacturers have already been doing with Shell.

In September, the candidate fuels will begin testing at the FAA’s Williams J. Hughes Technical Center near Atlantic City, New Jersey.

Cost factor

Many pilots are concerned about what the replacement fuel will cost. While it is impossible to estimate a final cost because of the multiple factors that make up the cost of a fuel—the components in the formula, distribution infrastructure, taxes and fees, etc.—Midgley said that a replacement is “unlikely to be cheaper … at least not significantly cheaper.” He explained that from a component standpoint, what is going into the unleaded fuel costs about the same as the components that go into leaded avgas. However, the component cost is a “small portion” of the overall cost of the fuel.

The new fuel also could enjoy a larger market than leaded avgas. Midgley pointed out that would be good news for the light sport aircraft industry. LSA engines don’t like the lead in avgas, but they also shouldn’t run on gasoline from the pump that has ethanol in it. A lead-free, ethanol-free aviation fuel would be beneficial to that market.

Peace of mind

Beyond ensuring the right fuel is put into the aircraft and checking it for contamination, many pilots don’t give the fuel running through their aircraft’s engine a second thought, yet it is the one provision in an aircraft that is not duplicated and does not have a failsafe, said Midgley, who earned his pilot certificate in Europe.

The reliability and safety leaded avgas has offered aviation over the years is worth celebrating, he said. “The industry as a whole can take a pat on the back.”

And that’s the bar the fuel companies are aiming to meet with the fuel replacement. “We as an industry need to make sure it is intrinsically safe when it goes in the aircraft,” Midgley said. “At the moment, we worry about that so you don’t.”

Rotors2Planks
08-07-2014, 12:57 PM
While it is impossible to estimate a final cost because of the multiple factors that make up the cost of a fuel—the components in the formula, distribution infrastructure, taxes and fees, etc.—Midgley said that a replacement is “unlikely to be cheaper … at least not significantly cheaper.”

Well that's kind of an important point. I'm not sure how much I care if it doesn't have any impact on the affordability of flying.

JamesNoBrakes
08-07-2014, 09:36 PM
Well that's kind of an important point. I'm not sure how much I care if it doesn't have any impact on the affordability of flying.

How expensive would it be if they didn't come up with an alternative when shell decides to stop refining 100LL?

Cubdriver
08-08-2014, 06:13 AM
Could be kind of expensive when the EPA sues the avgas industry for violating its lead-free deadline. And not to start another eco-politics debate, but lead free is a lot better for everyone which is why EPA insists on it. Lead has been linked to brain damage in children (same as lead paints) and the negative health effects are expensive to say the least. Unfortunately the cost is going to be high while R&D costs are recouped on the new lead-free fuels. I share your hope it will come down at least to current avgas prices in a decade or so; competition will drive it back down in time.

USMCFLYR
10-17-2014, 05:46 AM
Well this would count as an alternative fuel...........

Lockheed Says Its Fusion Reactor Could Power Airplanes - AVweb flash Article (http://www.avweb.com/avwebflash/news/Lockheed-Says-Its-Fusion-Reactor-Could-Power-Airplanes222910-1.html)

rickair7777
10-17-2014, 07:05 PM
Well this would count as an alternative fuel...........

Lockheed Says Its Fusion Reactor Could Power Airplanes - AVweb flash Article (http://www.avweb.com/avwebflash/news/Lockheed-Says-Its-Fusion-Reactor-Could-Power-Airplanes222910-1.html)

:eek::eek::eek:

This would power a lot more than airplanes...If it's for real. I'm astounded that this is not more publicized if they're far enough along to be taking about aviation applications.

USMCFLYR
10-18-2014, 06:07 AM
:eek:


This would power a lot more than airplanes...If it's for real. I'm astounded that this is not more publicized if they're far enough along to be taking about aviation applications.
I have no reason to doubt that 'Skunk Works' isn't capable of some pretty amazing feats! The "hundreds of millions of degrees..." comment is a little scary when thinking of aviation applications though. :eek:

WARP SPEED Scotty!!:D

CrimsonEclipse
10-18-2014, 11:34 AM
:eek::eek::eek:

This would power a lot more than airplanes...If it's for real. I'm astounded that this is not more publicized if they're far enough along to be taking about aviation applications.

New technology usually evolves as follows:

1. Laboratory
2. Land
3. Sea
4. Air
5. Space

Give it time.

Cubdriver
10-18-2014, 01:04 PM
As if turbine aircraft are not outrageously expensive as it stands, hard to see the cost case for going nuclear. We've had nuclear vehicles since the 50's in submarines, it only makes sense if the vehicle can't access other fuels easily. Just because a patent app is put in does not mean they are very serious about it- Airbus just patented an airplane with a windowless cockpit and there are tons of other far-out patents in the system.

CrimsonEclipse
10-18-2014, 02:29 PM
There's no comparison between the 1950's tech and the technology breakthrough by Lockheed.

One of the technologies was the direct to electricity without the need for a steam conversion. Electric airplanes would be a wonderful thing.

Again, I do not expect it in the near future. You'd first see it on electrical power plants, then ships (first military then civie), then special use aircraft.

Then more exotic applications.



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