US administration blames foreign pilots for 737 Max crashes

[infrequentflyer789]

Originally Posted by fdr

Is crew training of a lesser standard overseas? Well, before the CEO of Boeign goes on record on that matter, was he aware that Boeing is or has been the training provider for Ethiopian???? Seems kind of odd to bitch about standards, when the legally responsible party to the standards is.... Boeing.

This is perhaps my biggest issue, Boeing simply cannot have it both ways and now say that the pilots were not adequately trained for the MAX when they themselves said (quite loudly, and apparently betting $$$ on it) that the existing training that the pilots had was adequate for flying it (with addition of one iPad session - and no one has yet stated that ET or Lion crews had not done this additional training).

With the existing training the NG has a fatal crash rate of 0.06 (per million flights), while the MAX is at 3 (50 times the NG rate), which would be top of the table if not for Concorde. Neither of the MAX crashes had any adverse assistance from weather or poor visibility or external factors (PR-GTD), as several of the NG crashes have.

Take out the rhetoric and racism, and fix your plane guys. Suggest that you test your products with the intent of 25.255(a) not just the inadequate words that have so grossly failed us,

Looks like this might have been happening, from e.g. https://www.satcom.guru/2019/05/the-beat-goes-on.html quoting the hearings:

What is new is that MCAS stab authority will be limited based on available elevator pitch up authority - that the elevator will be able to apply 1.5g pitch up after one MCAS stabilizer trim command.

I don't think it is coincidence that the ability to apply 1.5g pitch up is one of the requirements of 25.255. Could be wrong though, the number may have come from somewhere else, and I don't suspect we'll ever see an admission that it wasn't in compliance before.

[LEVC]

Originally Posted by Lonewolf_50

How soon we forget. Go back over the past 10 years. Have any 320's gone down? Where?
(At least 1 737 has gone down in that time also ... we had an extended discussion here on PPRuNe on one that went down in Russia)
Suggest you also check gums' post. (IMO, the politicization of this is zero value added ... )

One A320 that went down in the past 10 years https://en.wikipedia.org/wiki/Indone...ia_Flight_8501

[Bend alot]

Just to be clear -
Interesting is the fact until the 737 MAX crash Ethiopian Airlines had a similar safety record to the United States over the last 12 years.

Or put another way over the decade from 11 Feb 2009 - 2019 Ethiopian airlines had a perfect safety record compared to the United States of 51 fatalities (+ cargo ops crew and jump seater's) for the same period.

[FrequentSLF]

My 2 cents...
MAX was designed to be a replacement of older 737, thus all the grandfathering, no need of training (other than an IPAD session)... which means that the plane was designed to be flow by pilots that are flying older 737... there was no commercial requirement to get grab market from AB, and retrain the pilots from AB to MAX, the whole business plan was to keep existing 737 customer buying an "upgraded product"!
Now FAA, Boeing, pilots in the "western countries" are saying... that those pilots in 3rd countries that have been flying the older 737 are not skilled enough to fly a plane that has been certified with grandfathering from the very same planes that they have been flying for the past 40 years...
I do not get it, can someone from "first world country" can explain me?

[futurama]

Originally Posted by Bend alot

Or put another way over the decade from 11 Feb 2009 - 2019 Ethiopian airlines had a perfect safety record compared to the United States of 51 fatalities (+ cargo ops crew and jump seater's) for the same period.

What? First of all, you're comparing apples vs. oranges. But even then:

• January 2010, ET409 crashed in Lebanon due to "flight crews mismanagement of [speed, altitude, and headings]". All 90 passengers and crew perished.
• February 2014, ET702's co-pilot decided to hijack (!) his own plane, over Sudan, with nearly 200 passengers on board. He flew to Switzerland where the plane ran out fuel on approach and managed to land with one engine operating.
• January 2015, ET 737-400F cargo destroyed in Ghana when pilots lost control of the aircraft during landing at Accra.
• March 2019, ET302 happened.

[L39 Guy]

Originally Posted by edmundronald

The original Boeing 737 entered airline service in February 1968 with Lufthansa. In 1968 they didn't do digital processing and Kalman filtering of flight instrument data. In other words the MCAS system is based on recent tech, the MAX is to some extent a hybrid of old and new, and thus the type certificate which was based on validating an entirely mechanical design should not have been extended without a very painstaking review.

After the pitch-down incident of QF72, the fault was pinned on bad processing of AoA data. The final report dwells in detail on the *novel* difficulties posed by the validation of digital systems and the problems posed by complex systems. Incorporating a new system for attitude correction (MCAS) and digital processing in the 737 raised both of these issues, and allowed new problems to creep unnoticed into an old design.

Let me try and be clearer - a pilot knows that if your airspeed falls too low, the plane stalls. An engineer knows that if you add a computer to an existing design of a mechanical machine you get an unpredictable new design that will be unpredictable unless it is tested to death. This is engineering 101, and the guys at Boeing who added MCAS to the Max knew it, the FAA guys knew it, and in the end the pilots who tested it to death proved it yet again.

Edmund

Your analysis is largely correct except that Boeing assumed that pilots would be able to manage this situation as an MCAS failure exhibits identical characteristics to a pilot as a well known emergency, Stab Trim Runaway that has been in the 737 (and virtually every other aircraft with electric trim) emergency checklist and training regime since day one.

And they were proven correct with the Lion Air incident the day before where the crew managed the situation and flew the remainder of the 1 1/2 flight. Boeing and every other aircraft manufacturer knows that engines are going to fail periodically and they count on the pilots, trained to manage engine failure events at the most critical time (just prior to or just after V1, the go no-go decision speed) to manage the situation.

[L39 Guy]

Originally Posted by futurama

What? First of all, you're comparing apples vs. oranges. But even then:

• January 2010, ET409 crashed in Lebanon due to "flight crews mismanagement of [speed, altitude, and headings]". All 90 passengers and crew perished.
• February 2014, ET702's co-pilot decided to hijack (!) his own plane, over Sudan, with nearly 200 passengers on board. He flew to Switzerland where the plane ran out fuel on approach and managed to land with one engine operating.
• January 2015, ET 737-400F cargo destroyed in Ghana when pilots lost control of the aircraft during landing at Accra.
• March 2019, ET302 happened.

You are correct in noting these accidents, two of which are fatal. That, in 9 years from a fleet of 82 aircraft today.

Bend alot likes to cherry pick data including an earlier post with a start date shortly after the Lebanon accident to demonstrate that US air carriers are equally unsafe. But consider in the US, Southwest alone has 750 B737's, United 768 jet aircraft, American 960 jet aircraft, 886 jet aircraft. And I am not including JetBlue and the others. Thousand of jet airliners flying every day and only a single passenger fatality in the past 10 years. That's impressive. Consider that BA has 274 aircraft, KLM 120, Lufthansa 310 and they have not had a fatality that I can think of for decades.

Lots of airplanes, lots of flying hours, millions of passengers of decades with such amazing accident records. That is no fluke. 2 fatal accidents in 9 years from 89 aircraft, Lion Air 1 fatal but many more close calls including landing short of the runway and into the sea with no fatalities (luckily) in less than five years with a fleet of 117 aircraft. That's not good.

As I stated earlier, "western" air carriers should not be ashamed or embarrassed to point out their safety record. These are facts. Just take a look at where all of the accidents are happening these days and that tells the story.

[Smythe]

Today it was reported that the MAX sims do not replicate MCAS recovery procedure properly and a software fix was required.

Has anyone been in a MAX sim? Did they use the stab trim switch config from the NG or the MAX?

Stab Trim Runaway that has been in the 737 (and virtually every other aircraft with electric trim) emergency checklist and training regime since day one.

Sorry, but the STS runaway for the NG is not the same for the MAX due to the differences in the functionality of the stab trim switches...

also note that in sim testing, even at 250 kts, the manual trim wheel would not budge and they had to roller drive the ac to move the stab...IF that is the case with the MAX, that is a problem and outside of STS procedures, no?

[L39 Guy]

Originally Posted by Takwis

False. The classic stab trim runaway is a stuck, or fused switch, which causes the trim to run "continuously", to the limits of the jackscrew in one motion. The characteristics of an MCAS input are actually closer to those of the STS, i.e. intermittent running of the trim, starting and stopping. Pilots that fly the 737 are very used to the STS trimming in the background on departure, and generally ignore it. MCAS is "identical" to neither situation, but closer to "STS running backward", as the surviving crew noted in the logbook.

There is a very good thread in the tech section, I suggest you educate yourself by going to read through it: B-737 Speed Trim System

Really? Show me where in the Boeing manuals that a Stab Trim Runaway is a case where the trim runs continuously to the limits of the jackscrew?

And how, as a pilot if you are a pilot, are you to determine if the trim reaches the jack screw or not? I would also suggest that any competent pilot will react to a trim runaway long before it reaches the jack screws.

Or would you just watch it run continuously, pitch the nose down 40 degrees then wait until it stops (at the jackscrew limit if you determine that) and then say "This must be a stab trim runaway as I think it has now reached the jack screws".

Or would you just watch it run continuously, pitch the nose up 40 degrees then wait until it stops (at the jackscrew limit if you determine that) and then say "This must be a stab trim runaway as I think it has now reached the jack screws"

Or would you cut the stab trim out after maybe 5 degrees of nose down (or up) attitude and recover

I know what I would do.

According the the NNC, a Runaway Stabilizer is defined as: Uncommanded stabilizer trim movement occurs continuously. STS is commanded trim, for those that are shown it in training and is a perfectly normal trim response. How do you define continous? 1 second, 5 seconds, 10 seconds, a 60 seconds?

As far as educating myself on the trim system, I have 16 years of B737 experience. How about you?

[gearlever]

Originally Posted by L39 Guy

Really? Show me where in the Boeing manuals that a Stab Trim Runaway is a case where the trim runs continuously to the limits of the jackscrew?

And how, as a pilot if you are a pilot, are you to determine if the trim reaches the jack screw or not? I would also suggest that any competent pilot will react to a trim runaway long before it reaches the jack screws.

Or would you just watch it run continuously, pitch the nose down 40 degrees then wait until it stops (at the jack screws if you determine that) and then say "This must be a stab trim runaway as I think it has now reached the jack screws".

Or would you just watch it run continuously, pitch the nose up 40 degrees then wait until it stops (at the jack screws if you determine that) and then say "This must be a stab trim runaway as I think it has now reached the jack screws"

Or would you cut the stab trim out after maybe 5 degrees of nose down (or up) attitude and recover

I know what I would do.

According the the NNC, a Runaway Stabilizer is defined as: Uncommanded stabilizer trim movement occurs continuously. STS is commanded trim, for those that are shown it in training and is a perfectly normal trim response. How do you define continous? 1 second, 5 seconds, 10 seconds, a 60 seconds?

As far as educating myself on the trim system, I have 16 years of B737 experience. How about you?

The trim is always via the jack screw, isn't it?

[L39 Guy]

Originally Posted by Smythe

Sorry, but the STS runaway for the NG is not the same for the MAX due to the differences in the functionality of the stab trim switches...

also note that in sim testing, even at 250 kts, the manual trim wheel would not budge and they had to roller drive the ac to move the stab...IF that is the case with the MAX, that is a problem and outside of STS procedures, no?

True about the differences in the functionality of the trim switches however the emergency procedure is identical, i.e. turn off both switches, is it not?

I can't speak for the simulator, its manual trim system and its fidellity but how do you explain the Lion Air incident crew (the day before the accident) being able to manually trim with the trim wheel after switching off both stab trim switches and flying for 1 1/2 hours to the planned destination and landing? Or do you think they strong armed it for that hour and a half? I suspect that they were able to crank the trim wheel.

[L39 Guy]

Yes, it runs via the jackscrew but one does not let it get to the limit of the jackscrew before taking action on a stab trim runaway.

[Takwis]

Originally Posted by L39 Guy

STS is commanded trim, for those that are shown it in training and is a perfectly normal trim response.

OMG, this is hilarious! So if STS is "commanded trim", and if the MCAS is merely software driving the trim through the STS system, then that means (drum-roll, please)... MCAS is "commanded trim"! Therefore the checklist does not apply!

[A320ECAM]

Well it was pilot error on both accidents.

Lion Air: the previous flight was saved by an off duty pilot jumpseating.

Ethiopian: aircraft was flying too fast because they never managed the throttles during the entire accident. Let me guess, straight after takeoff the PF's hand never returned to the throttles like any skilled pilot's hand should!

So my question is, would any AA/Delta/United/Air Canada/BA/Emirates pilots have the same trouble?

[Junkflyer]

Originally Posted by Old Dogs

American pilots are far superior to all other pilots around the world, .....

.... I guess. 🤔

In all fairness, the SWA flt fatality occurred due to an uncontained engine failure breaking a window-the fatality was sucked into the window frame and was killed.
The National Airlines was unrecoverable due to massive weight shift.
UPS flight in the desert was a cargo fire due to lithium ion batteries, not pilot error.
Really can't fault the crew in these three.

[L39 Guy]

Originally Posted by Takwis

OMG, this is hilarious! So if STS is "commanded trim", and if the MCAS is merely software driving the trim through the STS system, then that means (drum-roll, please)... MCAS is "commanded trim"! Therefore the checklist does not apply!

STS is an expected trim action that one learns about and experiences with the procedures trainer, simulator and his or her first line trip. Moreover, STS works to bring the aircraft into trim, not out of trim. There are no surprises here.

Having the trim system pitch the nose down with 10 seconds of trim with MCAS or any other reason where trimming action is not expected is “uncommanded trim” and is a surprise. A big surprise.

Have you been able to find the reference stating that a stab trim runaway has to go to the stops yet? I am anxious to see this.

[L39 Guy]

Originally Posted by Takwis

I suspect that they weren't as far out of trim.

They experienced the full meal deal MCAS so I would suggest that they were way out of trim too.

The big difference between them and the accident flights is that they executed the UAS drill after takeoff, flew the aircraft and controlled the speed making manually trim wheel possible after the stab trim shutoff switches were activated.

[Dualbleed]

Time for a warning that tells that stab is trimming when not supposed to.

[L39 Guy]

Originally Posted by Takwis

It doesn't need to mention the jackscrew in the manuals...that's where it goes. When it hits the end, it has to stop. Classic "runaway trim" is, as I said, a stuck switch, or fused, or a short somewhere, and the motor is going to run it to the end, barring any pilot intervention. Boeing is trying to say this is just like that, for legal reasons, and there are plenty of pilots to join in on the chorus, but the fact is, an MCAS activation is NOT identical.

You could still stand to do a bit of reading, about other pilots experiences in the plane that may not have happened to you. Somebody in one of the threads said they had seen the STS go for 10 seconds. Hmmm, what's that look like? I flew with a guy last month that had a runaway trim in an E-6 (707). Kept going after they cut off the switches, even. Wrong grease on the screw. Ever grab a spinning trim wheel and make it stop? You'll hurt yourself, maybe break a thumb if you do it wrong.

The source of the activation is academic, the result is what matters and the result is the aircraft not doing what the pilot, manually flying it, is commanding it to do.

As far as Boeing CYA, how would you word a Stab Trim Runaway that would cover all possibilities? How many Stab Trim Runaway checklists would you like to have and have to memorize? Do you really want to be diagnosing the problem while your hair is on fire fighting with the airplane ?

A fundamental difference between STS and MCAS is that STS is trimming the aircraft toward the trim for the speed, C of G, etc, and not working against the pilots and not pulling the controls out of their hands. Whether that takes 1 second of trim or 10 seconds of trim or anything in between, the system is working as it should and with the pilot not against it.

Stopping the trim wheel with your hand will definitely take a couple layers of skin off; using the bottom of one’s shoe works pretty good.

[L39 Guy]

Originally Posted by Takwis

You have evidence they experienced the MCAS trimming to zero units, full nose down?

No, I am relying upon the preliminary report from the accident flight and it does not have any detail of where the stab trim went to before they did the stab trim NNC. Perhaps they thought that waiting to hit the jacks crew stops (0 units) was not a wise idea. I would agree.

But what I do know is that they did the UAS drill, according to the report, managed to control the airspeed making manual trimming significantly easier compared to the accident flights roaring around at Vne and flew to their destination with manual trim and in stick shaker.

In other words, they did exactly what was expected of them as professional aviators.