When are you most likely to be hand flying? Close to the ground on departure and arrival. Kind of a bad time to have the yoke yanked out if your hands.

I would normally agree with you.

But ever since our president started with that b.s. I’ll have to agree that we need to source someone’s “facts” otherwise it’s b.s. like 99% of the b.s. coming out of that office.

The Emergency AD released for the MAX sheds some light on the system and what MAX pilots can expect if MCAS malfunctions. Some of the highlights include:

• If the autopilot is on or the flaps are extended, MCAS will not act on faulty AOA data.
• MCAS is limited to trim in 10 second increments, at 2.5 degrees max per increment, at a rate of 0.27 degrees per second. This is not a sudden nose-dive into the earth, but rather a gentle and slow buildup of nose-down trim.
• If stab trim is used to stop malfunctioning MCAS, it will restart 5 seconds after the trim switches are activated.
• The only 100% effective way to disengage the system is to move both STAB TRIM switches to CUTOUT and leave them there for the rest of the flight.
• IAS DISAGREE, ALT DISAGREE, AOA DISAGREE and FEEL DIFF PRESS are all potential alerts that may be associated with erroneous AOA data.

Again we don’t know the cause of this tragic accident. MCAS is not inherently bad. However, coupled with erroneous airspeed indications I think it can overload the crew.

I know that’s what the checklist says, but from a systems standpoint I think you would only need to turn off the switch for the autopilot trim. Then you could still use the trim switches on the yoke and not have to deal with the crank handles.

Alternate facts and lies are officially permitted under the current administration.

It's acceptable to remove data which contradicts those lies, and even convene panels of biased "scientists" after sacking the experts, to try to disprove existing fact.

It is acceptable, under the current administration to change the story to a new lie on a daily basis.

Alternate facts. Everywhere you want to be. No supporting evidence required. Anything which disagrees shall be deemed "fake news."

You're technically right, but there's strong indicators pointing to MCAS at this point. China and other countries have taken the stance of "why take the risk?" until more is learned, which is a position I can completely understand. When two brand new transport category airplanes of the (normally extremely safe) same exact type crash just months apart under strikingly similar flight conditions, it's ok to get suspicious.

If two kids disappeared 5 months apart while walking by the house at the end of your street, would you wait for the police report to stop letting your kids take the same route home from school?

This ^^^^^^
Thank you, PlaneS.

These weren't kids. They were aircraft. Opposite sides of the world. Different continents. Not at the end of the same street. Different companies.

The only two commonalities presently known are three: both were the same type aircraft; both involved a crash, and both are under investigation with the common link that we don't know what happened in either case.

If two prius crashed somewhere in the world, would you refuse to drive a prius? If two people choked on a hamburger somewhere in the world, would you refuse to eat a humburger? If two people on two different airlines on two different continents got sick from the same brand of inflight food, would you refuse to eat again? Straw and irrelevant, all, much like the mythical kid on the street, though that example is worst of all, as it implies and assumes too much of the irrelevant.

Many moons ago I had a job interview for a Cessna 207 in which the owner sat in the right seat and directed the trim run full nose up. Take off, fly a left pattern at 200, and land. Run trim full nose down. Takeoff, fly a right pattern at 200' and land. It's not the way I would conduct a screening flight, but I've seen weirder and worse. His view was that many pilots wouldn't think to keep the airplane slow and manageable, and wouldn't focus on flying the airplane; he could tell from the pilot's reaction and behavior, quite a bit about the makeup of that pilot.

While I don't advocate that practice, there are those who seem to feel that automation is there to fly the airplane for them, to do the dirty work of actually manipulating controls, and who all but advocate decision making to alerts, displays, annunciators, messages, etc. A trim which moves at a third of a degree/second isn't really an imminent threat unless one isn't flying the airplane. If one takes off, goes to automation, and waits until it runs far enough to disconnect the autopilot with a full deflection, then accelerates, the problem may become harder to handle than it needs to be; it's not like the warning signs aren't there, if one is flying the airplane and staying situationally aware. Even with automation engaged.

Presently we don't know what happened. Speculation is neither professional nor warranted. An investigation is underway. The FDR is in hand. It's prudent to wait to see what is revealed.

So how many of you 737 drivers have practiced erroneous airspeed indications along with simultaneous trim runaway while hand flying in the sim?

Same exact type of aircraft. Same exact phase of flight. Same issues reported immediately before the accident (airspeed/AOA). Why are you ignoring the obvious?

Following that logic, if 2 more MAXs crash in 2019, both on climb-out within the first 15 minutes of flight, still before any accident reports have been published, would you keep going about your day pretending nothing is wrong? It could take years for the reports to come out. In the mean time, it would be prudent to apply a little bit of brain power & common sense and try to see what's going on here. The investigators aren't the only people with the power of examination: the burden of being cautious and alert is on all of us, and you shouldn't need an investigation report to spoon feed you information that you could deduce.

My example actually makes perfect sense; disappearances are fairly uncommon, as are aircraft accidents. And it's in your power to instruct your kids to avoid a location, or to simply drive them to and from school, much as a government has the power to ground an aircraft and mandate finding another means of transportation in the meantime.

Prius accidents? Choking on food? Food poisoning? Are you really trying to compare three everyday occurrences to airline accidents, which we can go decades without seeing? :rolleyes:

I'm not sure what your point is here...congrats on landing the job?

Have you been reading this thread? MCAS doesn't engage when the autopilot is on. It only is active when hand-flying. I'd recommend reading up on the system before you speculate where the problem is.

Speculation might keep people alive in the mean time before an accident report is published. Is it not prudent and professional to be prepared?

You are oversimplifying your comparison. We also know that both crash aircraft had reported issues with unreliable airspeed (the Lion Air aircraft had been written up multiple times for unreliable airspeed in the days before the crash and in the flight immediately preceding the crash. The Ethiopian crash crew had reported unreliable airspeed to ATC shortly before the crash), and that both crashed in the same phase of flight, at the beginning of the en route phase (The NTSB defines the en route phase as beginning at the first prescribed power reduction or 1,000 feet above runway elevation, whichever occurs first), a phase of flight that is statistically the safest.

I'm not speculating on the problem, bright spark. That's the point.

Perhaps you can simply shortcut the investigative process with raw speculative expertise, and guess the cause and solution into existence, and save everyone a lot of time and effort.

Speculation doesn't save lives. A solid investigative process does.

We don't speculate. We don't guess. We know. It's what we do. We're not paid to guess about takeoff distance, performance, fuel burns, time enroute, or the cause of a mishap. We don't guess on those things. We know. Until we know, there's no value in guesswork.

I guess the term "precautionary measure" has no meaning to you. Why is being proactive instead of reactive such a hard concept for you to understand?

When two accidents occur that are near carbon copies of each other, a bit of educated speculation isn't just "guesswork." Comparing that to calculating takeoff distance and fuel burn is absurd, but hey, that puts it on par with your other comparisons to car crashes and food poisoning :D

By the way, none of this takes away from my point that you don't understand how MCAS functions and should read up on that before commenting on the issue. It's not as simple as flying a 207 around the pattern with full nose-down trim :rolleyes:

Your reading comprehension is low, but the comparisons were ironic (perhaps why you don't understand) to illustrate the stupidity of your straw man argument regarding kids at the end of the street. No surprise at all that they sailed over your head.

Not at all surprising that you failed to understand the reason the 207 was mentioned.

I understand MCAS well, thanks.

What I also understand is that at present, the investigation is open, and it's not known that MCAS is at fault.

Speculation and all that, you see.

Or perhaps, you don't. Carry on with your guesswork and speculation. It's very professional.

Precautionary measures work when we know what we're taking precautions against. We don't take evasive maneuvers for traffic when we don't know where the traffic is. That would be...stupid.

By your logic, next time the barn burns down, we should dehorn all the cows. I know, you don't understand. It's okay, you're off the hook, as it may be too much to expect.

Well, one source estimates there have been 500,000 flights with this model aircraft and two fatal flight instances leading to a rate of 4.0 fatal flight instances per million flights. The 737 fleet as a whole is about .18 fatal flight instances per million flights.

with 40% active 737 max fleet grounded worldwide, folks shall think why.

read boeing's own statement below, they knew they had issues related to MCAS and has been working on software update since 1st crash.

we all need educated guess with some common sense. it is not too hard to see something there, even for folks who are not pilots and not in this industry.

new engine, CG changes, MCAS for cert process, new software (and bugs), only time can tell.

we probably shall trust faa as much as we trust fda who is known to work with big phama quite closely.


================

Boeing Statement on 737 MAX Software Enhancement

March 11, 2019 - The Boeing Company is deeply saddened by the loss of Lion Air Flight 610, which has weighed heavily on the entire Boeing team, and we extend our heartfelt condolences and sympathies to the families and loved ones of those onboard.



Safety is a core value for everyone at Boeing and the safety of our airplanes, our customers’ passengers and their crews is always our top priority. The 737 MAX is a safe airplane that was designed, built and supported by our skilled employees who approach their work with the utmost integrity.



For the past several months and in the aftermath of Lion Air Flight 610, Boeing has been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer. This includes updates to the Maneuvering Characteristics Augmentation System (MCAS) flight control law, pilot displays, operation manuals and crew training. The enhanced flight control law incorporates angle of attack (AOA) inputs, limits stabilizer trim commands in response to an erroneous angle of attack reading, and provides a limit to the stabilizer command in order to retain elevator authority.



Boeing has been working closely with the Federal Aviation Administration (FAA) on development, planning and certification of the software enhancement, and it will be deployed across the 737 MAX fleet in the coming weeks. The update also incorporates feedback received from our customers.



The FAA says it anticipates mandating this software enhancement with an Airworthiness Directive (AD) no later than April. We have worked with the FAA in development of this software enhancement.



It is important to note that the FAA is not mandating any further action at this time, and the required actions in AD2018-23.5 continue to be appropriate.



A pitch augmentation control law (MCAS) was implemented on the 737 MAX to improve aircraft handling characteristics and decrease pitch-up tendency at elevated angles of attack. It was put through flight testing as part of the certification process prior to the airplane entering service. MCAS does not control the airplane in normal flight; it improves the behavior of the airplane in a non-normal part of the operating envelope.



Boeing’s 737 MAX Flight Crew Operations Manual (FCOM) already outlines an existing procedure to safely handle the unlikely event of erroneous data coming from an angle of attack (AOA) sensor. The pilot will always be able to override the flight control law using electric trim or manual trim. In addition, it can be controlled through the use of the existing runaway stabilizer procedure as reinforced in the Operations Manual Bulletin (OMB) issued on Nov. 6, 2018.



Additionally, we would like to express our deepest condolences to those who lost loved ones on Ethiopian Airlines Flight 302. A Boeing technical team is at the crash site to provide technical assistance under the direction of the Ethiopia Accident Investigation Bureau and U.S. National Transportation Safety Board. It is still early in the investigation, as we seek to understand the cause of the accident.

Crewmembers have a lot to deal with on a trip by trip basis... increases the risk of distraction... MCAS activates... is it legitimate or a spurious event? Adding Exposing crews to potential risks is just not right...

The FAA should have taken the lead and called for an immediate grounding of the MAX until the problem has been PROPERLY analyzed diagnosed, and repaired.

The AD contains many words for an antiseptic and band aide fix to a problem that’s not fully understood.

Those analogies only work in a world that has almost no car accidents or chocking events.

It seems that if only a few of these aircraft had been delivered they all would be grounded by now. Boeing comes up with a system that removes the pilot's primary pitch yolk input when there is a perceived unsafe condition and then say a few lines of code will sort it all out?

Your arguments are unrelated to any kind of logic being discussed here. I fly the Max, am (after LionAir) familiar with MCAS, and it's pretty obvious but not confirmed that these two are very possible related. Grounding the jet is a pretty logical step vs hoping the next flight crew will be able to sort out what two others couldn't and resulted in 350+ deaths.

This is like the Comet fiasco.

I'm not going to comment on whether the Max should or shouldn't be grounded. However consider this: When the Chinese authorities decide to take the most conservative position on health and safety it is likely politically motivated. Ask your American-Chinese expat friends how the work environment is these days. They are VERY safety conscious particularly towards Americans these days. As in career ending checkride safety conscious. The Comac 919 should be ready soon.

Yes, I assume all of us with a geopolitical perspective can read between the lines on this. It was easier for the PRC to make this move than it would be for the FAA, but I don't think they did it eagerly since it does have immediate economic consequences.

The flip side is that the FAA may be too reluctant to do the hard thing. I'm actually watching EASA... they don't want to go there, but if they do it before the FAA that would be telling IMO.

That’s what I’m doing!

I think the FAA does a good job. Though I question how many computer programmers they employ in a department to check code. I am suspicious that the FAA is behind the times.

You lost me with 2 = 3... :confused:

Why not shut MCAS off on all Max. Probably a not simple cannon plug removal or CB pull but there should be a way and would be better than grounding. MCAS was a certification pencil whip and the interesting thing is that if you apply the FAA/Boeing AD procedure if it malfunctioned you are left with no autopilot and manual trim and the procedure does not even mention any dangerous flight regime to avoid because of possible non linear control feel or pitch up tendency.

Boeing is tied in Deep with lobbiest at the highest levels ... military budgets etc etc.

Even if this were TRULY a Boeing issue , it will be converted to be 2 percent their fault and the rest of the blame of a hundred other things besides Boeing ... pilots , training etc


At this level politics will protect boring probably more than truly deserved . Not saying it’s right , just saying it’s the way it is ... imo

I don't think the FAA checks code at all, you're right it would be beyond their abilities. They approve processes for quality control of code (and other things), and verify that those processes are followed mainly by checking that documentation is completed.

The extreme case of QC for code is what NASA uses for manned spaceflight... a Red Team. They have a group separate from the developers and QC folks who actually try everything they can think of to break the code. That's their sole job. I don't know if that's required for part 25.

In many technical areas the FAA relies on industry expertise to help develop the standards and processes... they simply cannot employ enough folks to do it all themselves, and they cannot attract the requisite talent on GS pay scales. But in aviation industry does have a huge incentive to not take advantage of the situation... hull losses cost billions, and knee-jerk political reactions can be far more detrimental than reasonable, cooperative compliance with the spirit and intent of the oversight.

Weeeellll....

As I was saying. The UK just shut down the MAX and BANNED it from their airspace.

Apparently air turnbacks were ordered :eek:

Boeing is digging in their heels.

A serious 2020 presidential candidate is calling for the FAA to ground them as well.

https://www.cnn.com/world/live-news/...ash/index.html

In my limited (12 years) experience at an OEM (not Boeing) DERs are pretty serious about their responsibilities; can be harder than the regulators, simply because it can come down on their heads.

GF

We can’t eliminate these systems due to our continued inability to not pull back on the yolk during a stall. MCAS is like when your doctor gives you medication for your symptoms instead of treating the problem, then the new medication has more side effects that are worse than the initial problem.

I don't think MCAS was designed to protect against stalls or somebody's preclusion to pull back in a stall. I think it was designed to counter a stickforce lightning in certain high AOA regimes which Boeing haven't really closely defined. But it probably was discovered in flight testing during windup turns and didn't comply with what the regs require.

I gathered that MCAS was required only to keep the pilot control forces within certification limits, not actually required for stall recovery.

Les Abend throws the flag...

https://www.cnn.com/2019/03/11/opini...end/index.html

Total miss understanding of what MCAS was put there for:

"typically during takeoff and landing. The nose pitching too high translates into an angle of attack (the angle between the wings and the air flow) that could potentially cause an aerodynamic stall.
What's problematic is that the MCAS system is invisible to pilots. As a matter of fact, Boeing failed to inform many airlines via the airplane operating handbook that it even existed. If the system has a fault, and it senses an aerodynamic stall that doesn't exist, pilots are left trying to wrestle an airplane that is heading for the ground because MCAS is designed to nudge the nose down, a basic recovery maneuver for all airplanes that are approaching a stall."

You mean like Russian collusion? Keep politics out of this Representative ****z. This isn’t CNN.

If two priuses out of the first 350 had batteries catch fire while driving down the road I would most likely avoid riding in a Prius until after the investigation.

Project much?? :D
Thank god you aren't actually in charge of making regulation and safety-related decisions on a bigger level, because all you do is make ad hominem and straw-man attacks and misunderstand the bigger issues. You're clearly past your prime, reminiscing about flying a 207 "many moons ago" around the pattern in blatantly unsafe conditions (which isn't impressive at all, by the way, but definitely gives us all a window into how you think - or don't). My advice? Stick to yelling at clouds and kids who stray onto your lawn, unless you can string together a logical argument on the internet, in which case I'll be waiting on here for you. It's ok if it takes you a few tries, I understand it's harder for some people :o

sanc·ti·mo·ni·ous

adjectiveDEROGATORY

making a show of being morally superior to other people.

synonyms: self-righteous, holier-than-thou, churchy, pious, pietistic, moralizing, unctuous, smug, superior, priggish, mealy-mouthed, hypocritical, insincere, for form's sake, to keep up appearances