Breaking news: Ethiopian Airlines flight has crashed on way to Nairobi

[Evan]

This guy has become one of my favorite Aviation Youtubers. He explains his experience as a pilot the first 5 minutes or so then goes on to explain why the MCAS problem is harder for even the best trained pilots to respond/recover from than a more run of the mill stabilizer trim problem. Anyways, this guy is trained on the 737 among many others and has spent most of his civilian career in 767 and 777. I am sorry if someone has already linked to this guy or video but he is as experienced as a pilot you can find when it comes to everything from single engine prop to multi engine jet.

https://www.youtube.com/watch?v=9Ts_AjU89Qk

He states that the MCAS system is designed to interface with the thrust control as well as the stab trim. That is new information. If the system pitches down while also increasing thrust, it becomes even more dangerous. This would also explain the reported speed issue. But I wonder if he is mistaken about this, as no other source, including Boeing, has mentioned a thrust function associated with MCAS activation.

He confirms that, with the full down stab trim and significant increased airspeed, pilots cannot overcome the situation with elevator. That makes the situation fatal.

Otherwise, he seems to confirm everything I understand about the system, the human factors and the steps taken by Boeing and the FAA.

So the question is: is he for real? (this is YouTube)

[Evan]

The New York Times is reporting today that Ethiopian had one of the rare 737-MAX sims in action......but hadn't yet trained the pilots of the accident flight on this sim!

Ethiopian responded today, claiming the reporting was wrong but didn't specify what was wrong about it. They also said that its simulator “is not designed to simulate the MCAS system problems.”

—?

Ok. So Boeing DID provide a 737-MAX sim, but that sim doesn't actually simulate the 737-MAX malfunction that has thus far downed at least one and possibly two aircraft???

https://www.nytimes.com/2019/03/20/world/africa/ethiopian-airlines-boeing.html

[Gabriel]

He confirms that, with the full down stab trim and significant increased airspeed, pilots cannot overcome the situation with elevator. That makes the situation fatal.

Unless the pilot trims up.

[Evan]

Unless the pilot trims up.

Maybe. Maybe not. I know from an accident investigation that the 707 had a protective function that limited trim force (a think it was some sort of clutch designed to slip at a certain load) to prevent dangerous stress loads from being transferred to the airframe. At a certain point, the aerodynamic force on the stabilizer becomes greater than this limit and thus the stabilizer can no longer be trimmed against it. Does the 737 have a similar protective limit? I don't know the anwer to that.

But, in any case, the pilot needs to think "trim up" before the pilot will trim up. If the CVR reports are accurate, the FO on the Lion Air flight got handed the airplane without the PIC ever saying a word about trim runaway. So no CRM in that respect. I know that a clear-headed FO should have realized that, but we are not talking about a clear-headed environment here.

[Gabriel]

But, in any case, the pilot needs to think "trim up" before the pilot will trim up. If the CVR reports are accurate, the FO on the Lion Air flight got handed the airplane without the PIC ever saying a word about trim runaway. So no CRM in that respect. I know that a clear-headed FO should have realized that, but we are not talking about a clear-headed environment here.

I don't have the answer, but I still don't get it. If the plane tries to pitch down and you are finding yourself needing to make too much back pressure to prevent it, or being unable to prevent it, a pilot needs to "think" to use the trim as much as you need to "think" to hit the brakes if a kid crosses in front of your car. Trim is something you use in every single flight and permanently while in manual flight to keep the stick forces where you want them. Since hour zero in the Cessna 150. It should be totally incorporated and instinctive.

[Gabriel]

I don't have the answer, but I still don't get it. If the plane tries to pitch down and you are finding yourself needing to make too much back pressure to prevent it, or being unable to prevent it, a pilot needs to "think" to use the trim as much as you need to "think" to hit the brakes if a kid crosses in front of your car. Trim is something you use in every single flight and permanently while in manual flight to keep the stick forces where you want them. Since hour zero in the Cessna 150. It should be totally incorporated and instinctive.

Unless they had a severe loss of situational awareness and they didn't realize that they were pitching down and diving (which I suspect will be part of what happened with the Atlas crash).

[BoeingBobby]

Sent to me a few minutes ago from my friend at Southwest. https://youtu.be/LVOwxV9dVmg

[Evan]

Sent to me a few minutes ago from my friend at Southwest. https://youtu.be/LVOwxV9dVmg

Couple of distinctions I'm not clear on... This pilot tells us that MCAS is there for stall recovery, but I'm under the impression is it there to prevent stall, to counteract a lift increase caused by the engine and nacelle repositioning that might cause an airplane at the edge of the envelope to pitch up into a stall. Also, he refers to 'control laws' but I this is a FBW term for systems with multiple, degrading 'laws' used to interpret pilot commands. MCAS seems to have a function, not a control law. If this were a full-FBW 797, then MCAS wouldn't be needed because the problem could simply be overcome with elevator control laws that limit the elevator command at the upper limits of the envelope (the way it does in the A320 - just ask Sully).

[Black Ram]

AoA disagree light will now be standard.
AoA indicators will remain an option

https://www.nytimes.com/2019/03/21/b...es-charge.html

[Peter Kesternich]

UTAir was a runway overrun, not a total loss of control that killed everyone on board. Also, Russia is not a third world country (even though they have the highest accident rate in the world, again).

There were less that 360 737 MAX-es flying, and almost 7000 NGs. One would think you should have done better?

There's your own post to which I replied:

When's the last time two NGs crashed 5 months apart in third world countries, captain know-it-all? Sorry, I meant s***hole countries.

You never said anything about "total loss of control" there, so I gave you a quote of two crashes resulting in a hull loss, just like you were asking for in your post... You also never asked for a percentage of MAX accidents versus NG accidents. Try to be more specific and concise and you will get more specific and concise replies. And where is the point in trying to put down other forum members with comments like

One would think you should have done better?

The same goes for comments about the quality of countries.

As for the third-world countries, what do you consider third-world from an aviation point of view? I think we should rather talk about countries with questionable safety culture and high accident rates... Russia is defintely up there with Indonesia, and even here there are differences. Travelling on Garuda or Aeroflot is one thing, travelling on Lionair or UTAir is something quite different...

[Black Ram]

There's your own post to which I replied:

You never said anything about "total loss of control" there, so I gave you a quote of two crashes resulting in a hull loss, just like you were asking for in your post... You also never asked for a percentage of MAX accidents versus NG accidents. Try to be more specific and concise and you will get more specific and concise replies.

True, I didn't give those specifics. But I believe the context was more than obvious. The MAX has a significantly worse safety record than the NG and the A320 in "third world countries". I think you got my point as well but wanted to troll me a bit? It's fine by me.
We are talking about serious crashes here. The UTAir one was a runway overrun in difficult meteo conditions. Runway overruns happen like every day. Yes, UTAir was a very serious overrun resulting in a fire, but it doesn't seem to be on the level of AF358.

Did you know that somewhere between (or before) the two Lockheed Electra whirl mode crashes there was one other hull loss when one ended up in the water? Was that accident a factor when the Electra was grounded because of the other two crashes?

If you so insist, I'll rephrase my question, though I think it's absolutely unnecessary - when is the last time 346 people died in NG crashes in a 5-month period? I won't mention any percentages of the total aircraft flying.

And where is the point in trying to put down other forum members with comments like.

I wasn't trying to put you down. You don't control the number of NG crashes. My point was, with so many more NGs, we should have been seeing a lot more Lion/Ethiopian-style crashes, if we assumed the MAX crashes are mostly due to the third world countries they operated in. Sorry if I didn't get my point across.

As for the third-world countries, what do you consider third-world from an aviation point of view? I think we should rather talk about countries with questionable safety culture and high accident rates... Russia is defintely up there with Indonesia, and even here there are differences. Travelling on Garuda or Aeroflot is one thing, travelling on Lionair or UTAir is something quite different...

I agree. Where exactly is Ethiopian?


I would wish to summarize a few things:

- Boeing was working on a software fix before Ethiopian 302 (yes, "to make a safe plane even safer" )
- Miulenburg phoned Trump when the global groundings began to ask him to not let the FAA ground the MAX (according to Leeham, and Leeham usually know what they are talking about)
- Congress probe started into the MAX certification process, then a DoT investigation was started, which now also involves the FBI
- AoA disagree light will be standard on all MAX planes as part of the fix.


All this implies something was not right.

[Evan]

AoA disagree light will now be standard.

So, no third ADIRU? No sdditional, backup AoA vane? Oh, but you get a light!

[Vnav]

..................]

Geez, didn't even make it 24 hours

[Gabriel]

Geez, didn't even make it 24 hours

Hey!!! You are alive!!!

[thor]

the two 737 max 8 fatal accidents initial findings both showed that the AoA sensors were at fault, which send incorrect data to the MCAS.
on low altitude and clear sky, what's the chance of that happening? maintenance problem?