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

[Black Ram]

I agree with much of what you say- but we do have questions about a few things.

Confusion: Gabiee made the point- there's a stall warning/stick shaker going off AND the nose is dropping and I don't really know what my airspeed is...and it's a higher workload environment and who knows what else is going on...

...maybe I should let the nose fall...

You say "BIG difference between being legal and being proficient!"

I think Evanie (and maybe even your SWA friend) have said, "They didn't even tell us about this?"…

It's a big ole kludge/duct tape to make you THINK the plane responds exactly the same to stallish stuff as the 737-Maxlav...Yeah- make them THINK it's exactly the same...

Not an ideal situation for proficiency.

Acknowledgement- there is that argument that another recent crash should maybe have been in their proficiency even if it wasn't addressed in formal recurrent training quite yet.

Yes, and also trim runaway has to be continuous to be considered trim runaway. MCAS interventions are not continuous. May the actual pilots here correct me if I'm wrong, but I believe it even say that in the manual.

[Gabriel]

Yes, and also trim runaway has to be continuous to be considered trim runaway.

Not true. Especially not in manual flight. There are autotrim functions in the 737 (even before the MAX) that work in manual flight but are there to HELP the pilot and reduce the need that he uses manual trim. Any uncommanded trim that doesn't help but deteriorates the situation (i.e. that finds the pilot making more force or needing to do more trim adjustments to counteract it) is a trim runaway.

https://www.youtube.com/watch?v=xixM_cwSLcQ

[3WE]

Yes, and also trim runaway has to be continuous to be considered trim runaway. MCAS interventions are not continuous. May the actual pilots here correct me if I'm wrong, but I believe it even say that in the manual.

I think there's general consensus that pilots should ordinarily catch and correct this...

BUT a distinct concern that this can come at high workload times and with confusing circumstances...maybe folks could get caught off guard on rare occasions...

...and probably more often than ideal...

The trim cutting off and on versus a 'traditional' continuous runaway probably does not help.

But circular argument- just trim up like you ALWAYS do during your albeit brief times of hand flying... (unless you might be stalling- let's run the circular discussion ANOTHER time...and another)

[elaw]

Never mind that's really only a semantic argument. You have a system that appears to be malfunctioning in a way that's negatively affecting control of the aircraft, and two switches right in front of you to turn the system off... turn the system off!

[3WE]

Never mind that's really only a semantic argument. You have a system that appears to be malfunctioning in a way that's negatively affecting control of the aircraft, and two switches right in front of you to turn the system off... turn the system off!

No it's not a semantic argument...

You ain't got no airspeed
You DO have a stall warning
You DO have the nose dropping

The location of the trim cutoff on Boeing 707's and 737-Minlavs is NOT my priority

(Ok- the replies here may be out of phase, continuous vs. intermittent trim is semantics...CONVERSELY, I can envision intermittent trim being easier to be missed in the heat of battle.)

[Civil-but-firm debate appreciated]

[Gabriel]

You ain't got no airspeed You have one airspeed fully agreeing with the standby airspeed and the other one disagreeing by a few knots
You DO have a stall warning
You DO have the nose dropping You feel that the nose tends to drop and that you need to apply increasing pull-up force to prevent it from dropping.

Fixed.

[Black Ram]

Not true. Especially not in manual flight. There are autotrim functions in the 737 (even before the MAX) that work in manual flight but are there to HELP the pilot and reduce the need that he uses manual trim. Any uncommanded trim that doesn't help but deteriorates the situation (i.e. that finds the pilot making more force or needing to do more trim adjustments to counteract it) is a trim runaway.

https://www.youtube.com/watch?v=xixM_cwSLcQ

Ok, then what about this:

https://i.imgur.com/ooDeK17.jpg

And yeah, I see it says "do not use for flight".

I have watched the Mentour video you linked and I find it very incomplete, as many have commented on it.

[Evan]

Just remember, there are 2 switches that have been in EVERY Boeing commercial jet aircraft since the 707 right in front of the First Officers knee within easy reach of both pilot's. Turning them off would have solved the problem. There is a BIG difference between being legal, and being proficient !

Nobody is arguing that the correct move here is to cut off the electric pitch trim.

The argument is that, first, you have to have situational awareness and be focused on the pitch trim aspect of this. That is, you have to be focused away from the stickshaker, the airspeed and altitude disagree warnings and whatever other things might have gone haywire as a result of the AoA vane malfunction. And then, even if you have focused on the pitch trim issue, you would first use the yoke switches to counter it. There, it stopped. Now back to the sticksha... oh, what's it doing now...

One outcome of all of this will be to fix the system. The other outcome I would really like to see is for pilots such as yourself to concede that startle, upset and confusing events can degrade your judgment somewhat. The Ethiopian crash happened so soon after the Lion Air crash, it is unthinkable that the pilots didn't know about the issue and how to handle it. Yet they didn't handle it. How could that be? There is an answer to that question, but you won't find it in the FCOM and it might not be one pilots want to hear.

The most important lesson that can be learned by Boeing is that nothing can ever be allowed to cause startle and confusion by the nature of its design. Once you embrace the reality of human factors, you realize that, when it comes to background automation, fail passive is the only true fail safe.

[Black Ram]

Never mind that's really only a semantic argument. You have a system that appears to be malfunctioning in a way that's negatively affecting control of the aircraft, and two switches right in front of you to turn the system off... turn the system off!

We know that Boeing was close to coming up with a fix before the Ethiopian crash. That means Boeing has been working on a fix since the Lion Air crash. I know, "so what" 😁😁

It also looks like EASA certified the MAX only after agreeing with Boeing that a special training session must take place for the MAX, specifically because of MCAS. It looks like Boeing has responded by hiding the existence of MCAS. Hence why EASA skipped the software fix meeting a few days ago.

[Black Ram]

The most important lesson that can be learned by Boeing is that nothing can ever be allowed to cause startle and confusion by the nature of its design. Once you embrace the reality of human factors, you realize that, when it comes to background automation, fail passive is the only true fail safe.

It has also been recently confirmed that MCAS was designed to rely on only one AoA vane.

[Gabriel]

Ok, then what about this:

https://i.imgur.com/ooDeK17.jpg

And yeah, I see it says "do not use for flight".

Do you know what PDMG is? Show me something that says BOEING.

[3WE]

Fixed.

Ok fine...bring facts in to the discussion.

Do you find think this is more confusing than what it should be and kind of likely to fool a crew every so often-albeit rarely.

Yes or no?

[Evan]

It has also been recently confirmed that MCAS was designed to rely on only one AoA vane.

We've known that since the Lion Air crash. "We" includes Boeing and the FAA.

Edit: ok, we (not including Boeing and the FAA) only suspected it. Now we all know it.

[Black Ram]

Do you know what PDMG is? Show me something that says BOEING.

Yeah, fair enough, it was all I had found. But as expected, it mirrors the real document:

http://www.737ng.co.uk/737-800%20Qui...0%28QRH%29.pdf

https://cdn.aviaforum.ru/images/2013...147668092a.pdf

I don't know if they are 100% legit

[Gabriel]

Nobody is arguing that the correct move here is to cut off the electric pitch trim.

The argument is that, first, you have to have situational awareness and be focused on the pitch trim aspect of this. That is, you have to be focused away from the stickshaker, the airspeed and altitude disagree warnings and whatever other things might have gone haywire as a result of the AoA vane malfunction. And then, even if you have focused on the pitch trim issue, you would first use the yoke switches to counter it. There, it stopped. Now back to the sticksha... oh, what's it doing now...

I mostly agree with the above, but you really don't need to have your SA focused in the trim, not initially at least.

One pilot should be flying the plane at all times, ESPECIALLY IN MANUAL FLIGHT. Your PRIMARY FLIGHT DISPLAY should be your focus of attention to do that, ESPECIALLY IN CASE OF AN ABNORMAL SITUATION. FLY THE PLANE FIRST. Assuming that one pilot is doing that, he will fight to keep the attitude where he wants it. If the yoke becomes heavy and you need to pull back on it with increasing force, an OBVIOUS AND NATURAL reaction is to apply nose-up trim. No matter how many times. If the plane is nosing down and you pull back as hard as you can but can't get the nose to go up, and OBVIOUS AND NATURAL REACTION would be to apply nose-up trim. Speed disagree should be of little relevance here. The stickshaker can be way more confusing though. I am about to stall? Should I pull up? Is the nose going down by itself because we are stalling? The fact that the pitch attitude is normal and the vertical speed is normal for that pitch attitude, and that when I pull up the plane does go up (that's at least what happened in Lion Air before the final dive) should be a clear indication that we are not stalling. Plus, the noisy trim wheel spinning forward is a clue that is hard to miss. But I understand that being behind my PC it is much easier to do this rational analysis than when you are in the cockpit not understanding what is it doing now. Again, we still don't have information about the Ethiopian crash, but the Lion Air one, the pilots were a good time controlling the situation with nose-up trim inputs, until they stopped (apparently when the control was transferred to the other pilot so the pilot flying could look at the QRH).

One outcome of all of this will be to fix the system. The other outcome I would really like to see is for pilots such as yourself to concede that startle, upset and confusing events can degrade your judgment somewhat. The Ethiopian crash happened so soon after the Lion Air crash, it is unthinkable that the pilots didn't know about the issue and how to handle it. Yet they didn't handle it. How could that be? There is an answer to that question, but you won't find it in the FCOM and it might not be one pilots want to hear.

This is the part that I don;t understand. I don;t understand how a pilot that was familiar with the known details of what transpired in the Lion Air crash could lose it to the same condition. Startle is not enough, not a second time. Use manual trim, evaluate the situation, keep using manual trim, eventually, kill the trim cutout switches. I am starting to believe that these pilots were not familiar with the details of the Lion Air crash, or got it wrong or incomplete.

The most important lesson that can be learned by Boeing is that nothing can ever be allowed to cause startle and confusion by the nature of its design. Once you embrace the reality of human factors, you realize that, when it comes to background automation, fail passive is the only true fail safe.

I thought you demanded 3 AoA vanes to keep it fail-operational rather than fail-passive which can be achieved with 2 vanes.