RustyC

This is reminding me more and more of that ValuJet crash. They were an airline rather than a manufacturer, but there was more to the story than just the crash and they had had a pattern of safety incidents and cutting corners before the fatal one that woke everyone up. The Atlanta local media fell asleep and bought into the idea that the airline was somehow a victim, and it took reporting by national papers to uncover the truth. The FAA also had looked the other way on far too much.

Not long after the airline restarted it had a merger and decided the ValuJet name just had to go (and it became AirTran). I think we'll also see the whole MAX 8/MAX 9 name wiped from the face of the earth. Boeing will do some kind of retrofit on every plane and just rename the model (737-1000?) Max will be put into total retirement and become a non-person at Boeing headquarters.

Plato90s

"There is no time" is a good choice of words, as this NYT article suggests

https://www.nytimes.com/2019/03/25/b...ion-error.html (bolding mine)
So once again, I believe it's true that pilots could have successfully saved both flights if they had done the exact right things.

The information I've seen to date also makes me think that Boeing cut the margin of safety far, far, far too thin when it comes to the 737-Max and the MCAS software.

LarryJ

Runaway trim has been a thing ever since we started using powered trim systems in the 1940s. MCAS doesn't change that. Actually, an MCAS runaway is slower, due to it's 5-sec pauses, than any of the other probable trim runaways. That gives you more time than you would have had for any of the runway trims that we trained for over the past 6+ decades.

It's also not unique to 737s. Every transport jet, and some of the G.A. airplanes, that I've flown have had a runaway trim procedure that I've had to know and practice. If aircraft systems have the ability to trim the airplane, and they must, then a runaway trim situation is possible.

The runaway stab procedure in the 737 is comparable to turning on your hazard lights in your car when you suddenly have to stop on a freeway. It literally takes less than five seconds to think about it then do it.

That's the appeal to authority fallacy. It would be like me saying here, "I'm a 737 pilot so you should believe my argument". When authorities disagree, as in this case, you just cherry pick the authority who agrees with you?

Instead, you should compare my argument to theirs and judge both on their merits.

I have explained why knowing more about MCAS does not help in handling an unscheduled MCAS activation. What have these other authorities said that convinces you that my arguments are wrong?

Plato90s

I would suggest that the behavior of MCAS was so unexpected that the pilots didn't recognize the problem properly.
In my view, your position is the same as Boeing's position - the pilots had the ability to save the plane.



My view is that is a technically correct answer which does not alter the fact that the primary reason over 350 people are dead is due to bad choices by Boeing.

They prioritized the ability to sell the aircraft with the promise of no-retraining against the safe operation of a passenger jet.

WHBM

Despite being in the Third World, and thus being despised by (some of) those from the manufacturer's country, the carriers had fully followed the Boeing official training. Which apparently is a PowerPoint presentation. It was not a Third World pilot but one from a US major has who described when they were unexpectedly presented with a Max for the first time both crew felt pretty much at sea with it, including instrument presentation differences that were not in the PowerPoint. Notably the switch to turn off MCAS has different labels to the comparable switch in the 737-800, for a reason nobody can understand. Wonder if that was in the PowerPoint.

The "optional" safety feature is a disgrace for Boeing, it seems someone has seen Nickel-and-Diming at rental cars and felt it was an appropriate way for an aircraft manufacturer. The UK Trident jet more than 50 years ago had AOA comparison as standard. I wonder if the FAA knew it was being offered as an option rather than standard, seeing as all the trial aircraft were for airlines who have ordered it. And I wonder what other safety features had been made optional, I somehow can't see this being the sole one. It's also curious that the whole MCAS thing seemed to develop during certification, rather than being original design concept, and by the time it was done and these additional warnings were needed, both the airlines in question had already signed contracts for it.

It's well established that no mention of MCAS had been made in any of the pilot training. Do you honestly think Boeing had in contrast, however, done huge amounts of documentation, spares provision, training and examples on the same feature for the maintenance crews ?

Is that an accurate description of their situation, though ? It wasn't only runaway trim. It seemed to start when an AOA error gave spurious Stall Warning and Stick Shaker to the crew, plus Unreliable Airspeed. There's long-established procedures for all those (probably since before the 1940s). What is new on the Max is that IN ADDITION the AOA error started bumping the trim down as well, while the crew are dealing with the cacophony from the other events.

In fact, given that you are established aircrew, can I please ask a question. Given that there are apparently few/no Max-specific simulators around, and training is on the supposedly-similar 737-800 ones, how often have you been given a training simulation with Spurious Stick Shaker PLUS Spurious Stall Warning PLUS Unreliable Airspeed indication PLUS Runaway Trim, all at the same time ?

hull22

SWA 737 Max emergency landing
https://www.orlandosentinel.com/news...326-story.html

LarryJ

Would a stabilizer runaway due to a failure in the Speed-Trim-System or a shorted electric trim wire, have been any less unexpected?

There is no difference in the stab trim cutout switches. (Where did you see that reported?)

Many of the failures that we're given in the simulator involve a number of warnings and indications which require us to priorities so that the correct checklist or procedure is accomplished first.

Read QF32. It is the autobiography of the Captain of QF32 which was a QANTAS A380 departing Singapore that had an uncontained engine failure which damaged every major system on the airplane. He recounts the flight in great detail, including the exact times of compound problems that you've described, and how they dealt with them.

I have had an AoA vane failure in a 737-700. It produced "IAS DISAGREE", "ALT DISAGREE", and "ALTN" on both engine's EECs. One primary airspeed indicator dropped to minimum (45kts) and the same-side's altitude display was wrong. We quickly verified which flight instruments were correct, ensured that the pilot-flying was the one with the good instruments in front of him, priorities the checklists for each indication and accomplished them in that order, and landed. I met that Captain for the first time 60 minutes before the flight on which all of that happened. Made for an interesting flight but it is exactly what we are trained to do even though neither of us had every been given that exact combination of problems in the simulator.

WHBM

There are side-by-side photos of the switch units from the -800 and the Max in the substantial PPRuNe thread on the event.

https://www.pprune.org/10429289-post155.html

tmorse6570

This plane obviously has problems.

jrl767

the engine overheat indication on the WN jet has absolutely nothing to do with the MCAS issue ...

TWA884

Other than the angle from which the photos were taken, those appear to be identical (the MAX panel is on the right).

chrisl137

I stared at it last night and it took me a while, but the text above the stab trim cutout switches is different. It's one line over each switch on the MAX and two lines on the NG. Location and other labelling appears unchanged.

chipmaster

An interesting read: https://www.eetimes.com/document.asp?doc_id=1334482

My simply distillation

1. Competitive market pressures requires BA to the only solution possible a 737 modification with new engines / wings etc. to compete​​​​​​. Fundamentally new engines on a airframe design from 40 years ago has some issue!
2. During development identified a fundamental issue with engine airframe integration that required a software patch
3. Business constraints with pilot training, fungibility, cost, biggest customer required 2) to subterfuge
4. Obviously internally they identified additional things like dual sensors, warning lights and I'm sure someone in BA suggested more explicit notification / training but because of 1) and 3) decided to do the "minimum" they needed versus what they could.
5. Lastly it is incomprehensible that they charged for extra safety, but is it different than if you build a house/building to ask for more $ for extra fire/smoke detectors or sprinklers, slippery slope of ethics and business and engineering. Hate to be the program manager that sat in on that meeting between the bean counters and the quality/safety and engineering guys.

Now the CEO and senior leaders should take a look at what JnJ did with their Tylenol and or Intel finally had to do with their FDIV. It is hard to admit you failed, but the longer they don't the worse it will be and all confidence will be lost. Of course AirBus can't look itself cleanly in the mirror as their closet isn't clean of skeletons either.

LarryJ

The switches are identical as is their function.

Are you saying that the slight change in labeling is a factor?

WHBM

Just to help, the "identical" switches are labelled :

737NG :


MAIN...........AUTO
ELECT..........PILOT


737Max :


PRI...........B/U