MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures

[Grebe]

A technical clarification is in order. At no time did the automation (i.e. MCAS) "override" pilot inputs.

Well pilots had been trained and on all previous to MAX, when pilot pulled( or pushed ) on yoke in opposition to trim direction, trim STOPPED.

But that never happened, since the appropriate switches / sensors had been bypassed or disabled due to incorporation of MCAS.

So splitting technical hairs - did MCAS override pilot input ??

[Tomaski]

Originally Posted by FullWings

Which would be fine if the manual trim was actually effective throughout the flight envelope but it seems it may not be, for practical purposes...

The underlying presumption in this particular case is that the pilots could have used the fully functioning Main Electric Trim to return the aircraft to somewhere close to an in-trim state before turning off the electrics. Yes, we know that didn't happen, and the reason why that didn't happen is an important discussion. However, we need to first recognize that the capability was actually there.

[etudiant]

That is asking a lot of Joe Pilot.
He's been taught to trust the instruments which are now driving him into the ground, for reasons he does not understand or know about. Plus his inputs are reversed at much higher speed by automatics he does not know exist.
I'd hate to be subject to that test, because I'm sure I'd fail it.
Where that leaves Boeing is beyond my competence, but I cannot see the regulators remaining oblivious.
Imho, the MAX is dead.

[ST Dog]

Originally Posted by jdawg

Just hate to see others here say the pilots should have simply established a pitch and set a thrust setting.

That's not what started this subthread.

The point was AoA indicator is not needed. That's why it was an option. It's not required by the FAA/EASA/etc.

You fly attitude and power not AoA.

[ST Dog]

Originally Posted by JPJP

This is what the alert looks like on the MAX PFD. It’s tiny.

Shows how unimportant it was considered and why there was no rush to push a fix.

[phylosocopter]

Originally Posted by ST Dog

That's not what started this subthread.

The point was AoA indicator is not needed. That's why it was an option. It's not required by the FAA/EASA/etc.

You fly attitude and power not AoA.

It was also not my intention to imply "the pilots should/could have just flown attitude and thrust" . Rather I was trying to have a discussion around the need for there to be an understanding that the automation can (and did in this and other situations) loose situational awareness , in such case it should not be raising any situational alarms or (as in this case) taking any action. In this case the FMC did know it was foo-bar but did not have a programmed response of shutting down all situational processes and alarms to a fail safe state. It could and should have!

[Tomaski]

Originally Posted by etudiant

That is asking a lot of Joe Pilot.

I agree that it would be a lot to ask of any pilot who had not been trained for a malfunction like this, but it is not inherently an impossible situation with the proper training. I think the germane question is whether changes need to be made to the current pilot training regimen. I can tell you from personal experience that until the MAX accidents, training for anything that looked like runaway stab trim had been spotty to non-existent at my airline (a reasonably well-regarded "developed world" operation). I suspect we were not the only ones who neglected this training for far too long.

[NutLoose]

Compensation being offered by Boeing over family losses is a pittance USA wise, I would have expected at least a naught on the end.

https://www.bbc.co.uk/news/business-49803068

[Grebe]

tomaski

I agree that it would be a lot to ask of any pilot who had not been trained for a malfunction like this, but it is not inherently an impossible situation with the proper training. I think the germane question is whether changes need to be made to the current pilot training regimen. I can tell you from personal experience that until the MAX accidents, training for anything that looked like runaway stab trim had been spotty to non-existent at my airline (a reasonably well-regarded "developed world" operation). I suspect we were not the only ones who neglected this training for far too long.

Lets see - Assuming pilot realized he had to use trim switch to get near level trim BEFORE hitting kill switch - how long did he have ? Seems to me he had at best 5 seconds - now with a typical call - response - action - how much ' slack ' was available ??

[jdawg]

Originally Posted by ST Dog

That's not what started this subthread.

The point was AoA indicator is not needed. That's why it was an option. It's not required by the FAA/EASA/etc.

You fly attitude and power not AoA.

So we agree AoA is not necessary but my question to you remains. How do you fly attitude in a loss of pitch control situation? Just wait for the pitch control to return on its own?
You don't understand the severity nor scope of the Max crisis. Ironically your strategy is exactly what the crews did, simply tried to fly an attitude. It didn't work.

[Fly Aiprt]

Originally Posted by JPJP

This is what the alert looks like on the MAX PFD. It’s tiny.

It looks more like a secondary indication than an alert.
The non-certified aviation seems to have a better grasp of human factor and ergonomics.
This is how a better thought out display could have looked like, with an alert in the direct field of vision of the pilot.
And an AOA indication at a useful place.

[Icarus2001]

How do you fly attitude in a loss of pitch control situation?

There was no "loss of pitch control". That is clear as the aircraft continued to fly until a hand over of control in the case of one flight. The elevator simply became "heavier" as MCAS wound in forward trim. Any pilot used to hand flying would then instinctively wind in back trim to lighten the control load. As Tomaski said above, why they did not do this is a germane point.

[babemagnet]

What are they doing all day!? Is it so difficult to certify an aircraft again! Every day has 24 hours how long can it take!

[.Scott]

Originally Posted by babemagnet

What are they doing all day!? Is it so difficult to certify an aircraft again! Every day has 24 hours how long can it take!

They are re-examining the recertification process. They'll be done when everyone is satisfied that they have it right. How long will that take?

[Tomaski]

I like! I like very, very much!

Originally Posted by Fly Aiprt

It looks more like a secondary indication than an alert.
The non-certified aviation seems to have a better grasp of human factor and ergonomics.
This is how a better thought out display could have looked like, with an alert in the direct field of vision of the pilot.
And an AOA indication at a useful place.

[DaveReidUK]

Originally Posted by Fly Aiprt

It looks more like a secondary indication than an alert.

At the time the indication was designed, presumably Boeing considered it to be purely informational.

Rather than a warning that there was a risk of the aircraft becoming uncontrollable and killing everyone on board ...

[edmundronald]

Originally Posted by DaveReidUK

At the time the indication was designed, presumably Boeing considered it to be purely informational.

Rather than a warning that there was a risk of the aircraft becoming uncontrollable and killing everyone on board ...

A condition that kills you in 3 seconds would justify a display and a circuit breaker.

I have no doubt that ten years from now an AoA/Mcas related fault will kill some poor bastards again.

Edmund

[Tomaski]

Originally Posted by Grebe

tomaski

Lets see - Assuming pilot realized he had to use trim switch to get near level trim BEFORE hitting kill switch - how long did he have ? Seems to me he had at best 5 seconds - now with a typical call - response - action - how much ' slack ' was available ??

Once the pilot is actively and aggressively engaged with using the Main Electric Trim, they have as long as they need. By design, MCAS would pause for 5 seconds every time the Main Electric Trim (yoke switch) was used, and there is no limit to how long the Main Electric Trim could be run at any one time. In theory, one long nose up trim input to put the trim back in place, then a series of short trim inputs every 5 seconds or so. The pilot could literally do this as long as they wanted until they either 1) ran the Runaway Stab Trim procedure to conclusion, or 2) slowed down to less than 250 KIAS (if not already there) and extended the flaps. Again, not an impossible situation to manage with proper information and training - and that is exactly what was missing.

If pilots were never properly trained to handle critical emergencies like engine failures and windshear during takeoff, we would not be surprised to see accidents when these events occur. But we do train for them, pretty much every single time we go through a sim session. How often were the accident pilots exposed to a Runaway Stab Trim scenario? I haven't seen one in years, though I expect that will probably be changing.

Yes, MCAS was a crap system and never should have made it past certification. Not informing crews of its existence was borderline criminal. That doesn't mean it was not possible for pilots to have been exposed to the type of training that would have allowed them to survive this malfunction. (And before anyone jumps on this bandwagon, I am NOT blaming the pilots. The pilots do not create the procedures, the training syllabus, or the corporate culture that gives a short-shrift to safety. However, they are products of all the above).

Specifically as to training and general operations, here are some areas that need attention:

• Automation policy. By their very nature, some malfunctions strip away the automation. The pilots need to be able to operate without automation/normal law AND respond to a critical malfunction. That only comes from regular practice flying without these aids. If it is an airline's policy that pilots operate at the highest levels of automation all the time, we should not be surprised when they become task-saturated when the automation is no longer there to assist them.
• Overly-scripted training. Pretty much every where, training has become a series of scripted malfunctions that are known in advance. Multiple malfunctions are not presented. There is little, if any, use of surprise or ambiguity. Real life does not go by script, nor is there any natural law prohibiting multiple or ambiguous malfunctions.
• Over-reliance on procedure, not enough big picture. Procedures are a pilot's bread and butter, and should not be disregarded lightly. However, every manufacturer will also state that they cannot devise a procedure for every situation. In certain situations pilots need to recognize when a situation does not fit a specific procedure (rather than going heads down looking for a procedure that does not exist), and rely on basic airmanship and systems knowledge to do what is necessary to stabilize the situation. If this concept is not instilled into flight crews, then they be poorly equipped to navigate the unexpected.

A thorough accident investigation provides an opportunity to identify and correct deficiencies throughout the entire chain of events. Yes, Boeing is responsible for the most egregious lapse in the chain, but there are other issues at work here and ought to be addressed as well. The problem, of course, is that the additional training outlined above will require an investment of time and money, and airlines are extremely cost-driven enterprises. They will be very reluctant to make this investment without outside pressure.

[OldnGrounded]

Originally Posted by Tomaski

Yes, MCAS was a crap system and never should have made it past certification. Not informing crews of its existence was borderline criminal. That doesn't mean it was not possible for pilots to have been exposed to the type of training that would have allowed them to survive this malfunction.

Sure, it could be trained, but there would be no need for such training if the system didn't do that. Presumably, going forward and assuming that the MAX gets back in the air, it won't do that -- a much better situation.

Edit: Also, there is some question about the likelihood of pilots promptly recognizing improper MCAS intervention, even if they know about the system. And, in the original version, if you didn't identify the problem and sort it out in 40 seconds, you and your pax were dead. It's OK with me if you want to try to train aircrews for situations like that, but I wouldn't want to bet my life on the results of that training.

[Tomaski]

Originally Posted by OldnGrounded

Sure, it could be trained, but there would be no need for such training if the system didn't do that. Presumably, going forward and assuming that the MAX gets back in the air, it won't do that.

I quite agree. Personally, I think it is very unlikely that MCAS will ever cause another aircraft accident. However, I think it is almost certain that in the not too distant future there will be another novel malfunction on another aircraft with another crew, and the specific training issues that I mentioned will be a factor in how well that crew responds.