Cubdriver

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

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

At least Lycoming is making flexible engines now, that's a start.

Cubdriver

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.

rickair7777

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

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 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

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

Continental president gets the lead out en route to AirVenture
from AOPA Online's
Thomas B. Haines

(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. 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

Grass for Gas: Flying a Real, Renewable Fuel

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

A New, More CO2-Absorbent Algae Strain?

By 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, 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, 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. 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, 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

Researcher: Military Qualifications Key To Alternative Fuel Race.

Flight International (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."