Ethiopia crash

[DellyPilot 109]

10 hours ago, KevinAu said:

then why did he not hold the trim down afterwards

This is indeed puzzling, but I believe it is because when he flicked them back on and the applied TRIM UP it made almost no difference to the pitch (look at the graph nothing happens). He wrongly assumed nothing was happening and although it did move a bit he didn't see feel pitch up so gave up, 10 seconds later and MCAS kills them. MCAS would have been differed if he had just held the TRIM UP constantly. Hopefully the full report determines which side was trimming and why he stopped.

10 hours ago, KevinAu said:

it would have been better if they had gotten to it earlier, before the second running of the trim or had pulled the power back. That’s why I separated it from the first 2 points and put the word ‘understandable’ there, to try to communicate to you that they may be errors in the final report, but nothing that should have been held against them.

That's very good to hear and I agree its all part of how the aircraft crashed, it took them only 20 seconds after the first event (05:40:30) to realise it was runaway trim and cut STAB TRIM switches. I think it showed good airmanship initally to keep trimming up after 05:40:30 before flicking the trim motors off at 05:40:40 just in time to prevent MCAS 3! So far so good. It's after disabling MCAS it starts to go wrong. Infact it is just then they reach VMO max. 
 

10 hours ago, KevinAu said:

Look at the fdr readout you posted, the plane had been climbing even after the first two mcas inputs. 

Small point, they reached 8400ra.

After the first 2 MCAS events it stays almost totally level (see graph). After the 3rd MCAS (05:40:40) event which didn't move the STAB because of the cutout switches they managed to climb with 20degrees back pressure.
What you notice from the stick angle and pitch disp charts is that he really is struggling more and more to keep the nose up and by the end 05:43:04 is asking the FO to help pitch up with him, even with 20degrees he cant keep the nose up despite doing 360kts! You say just keep going boys but he is about to start descending and he doesn't want to pull the power because that will pitch them forward even more.. the trim is totally jammed. No way out. Thats my speculation anyway!

Again in the cold light of day with all the facts from our couches we can all see they made mistakes.

The decision to not announce he was flicking the switches is pure speculation as the prelim report may be incomplete. But even then I think if its the captain who did it it makes little difference. He felt he had to get the trim switches working again and he didn't expect the HUGE effect the final MCAS event would have. 

http://www.ecaa.gov.et/documents/20435/0/Preliminary+Report+B737-800MAX+%2C(ET-AVJ).pdf/4c65422d-5e4f-4689-9c58-d7af1ee17f3e

[DellyPilot 109]

1 hour ago, Wink207 said:

Prior to the grounding there were 350 some odd Max aircraft in service having safely completed thousands of flights with no apparent AoA related incidents. This is a statistically significant number

Is it tho? 350 planes flew for ~6 months and we know of 2 with damaged AoA sensors. Both crashed (significant). The number of planes that flew with no AoA damage is irrelevant. Maybe some airports have more birds or more clumsy service crews.
 

1 hour ago, Wink207 said:

Also, there are more thousands of transport aircraft flying around with the same or similar AoA sensors.

Yes they probably get bashed about all the time, but all you get is a warning light, no MCAS!

[Christopher Low 5,352]

We can argue all day about whether the pilots made mistakes or not, but (IMO) the most important spect of the two incidents is if the aircraft did something other than expected when they followed procedure. All the training in the world is not going to prepare you for that scenario. I can imagine that even the cool, trained brain of an airline pilot would start to panic in a situation like that

[KevinAu 441]

1 hour ago, Christopher Low said:

We can argue all day about whether the pilots made mistakes or not, but (IMO) the most important spect of the two incidents is if the aircraft did something other than expected when they followed procedure. All the training in the world is not going to prepare you for that scenario. I can imagine that even the cool, trained brain of an airline pilot would start to panic in a situation like that

No, the ethiopean pilots did not follow the procedure. They turned the trim back on. The procedure explicitly says not to do that. The plane did exactly what one would expect in this failure scenario.

Reading through the preliminary report, what you don’t see is anybody calling for any particular procedure. No memory item callout, no qrh callout. Although the ethiopean minister said they followed all procedures, it is apparent that they were too busy trying to just fly the plane to go that far as to actually call for a memory item or open up the checklist to go through the actual procedure is. When the fo called for turning off the trims, that was by gut, not by any particular procedure. When somebody turned it back on, that was also by gut, and not any particular procedure.

[Wink207 78]

13 hours ago, DellyPilot said:

Is it tho? 350 planes flew for ~6 months and we know of 2 with damaged AoA sensors. Both crashed (significant). The number of planes that flew with no AoA damage is irrelevant.

Wikipedia claims the first Max was delivered in May of 2017. I just have trouble imagining that MCAS had not reared its ugly head prior to the two accidents. Or were there other incidents which were not reported as such because Boeing hadn't really emphasized MCAS in the minimal training that was given.

[Wink207 78]

1 hour ago, KevinAu said:

No, the ethiopean pilots did not follow the procedure. They turned the trim back on. The procedure explicitly says not to do that. The plane did exactly what one would expect in this failure scenario.

Reading through the preliminary report, what you don’t see is anybody calling for any particular procedure. No memory item callout, no qrh callout. Although the ethiopean minister said they followed all procedures, it is apparent that they were too busy trying to just fly the plane to go that far as to actually call for a memory item or open up the checklist to go through the actual procedure is. When the fo called for turning off the trims, that was by gut, not by any particular procedure. When somebody turned it back on, that was also by gut, and not any particular procedure.

Yes. Sadly, I believe the Capt lost situational awareness. From the report it seemed that he lost control of the airspeed and didn't really seem to understand that although IAS is good, too much IAS quickly becomes bad from a maneuvering perspective. I know he had an alert on unreliable IAS but the FO's side was good. And I believe the runaway trim MI list calls for A/P and A/T off. One last point also, although I dislike criticizing these guys, when the stick shaker started on his side and they could see the FOs side was still good, they did not discuss turning PF over to the FO. Maybe the Capt didn't feel comfortable turning it over to a very junior pilot? The FO really seemed to have pretty good SA.

 

 

Edited April 9, 2019 by Wink207

[threexgreen 3,139]

5 hours ago, Wink207 said:

they did not discuss turning PF over to the FO

In an emergency like that it's always the Captain who's PF because of greater experience and ultimate authority over the aircraft. Especially in this case as the FO was young and not very experienced. To substitute for the Captain's wrong data he can still refer to the standby instruments and the FO can call speed, altitude and pitch out. With the stab trim acting up and the struggle to keep it in the air you'd definitely want the more experienced cockpit crew member flying the aircraft.

[skelsey 765]

Just now, threegreen said:

In an emergency like that it's always the Captain who's PF because of greater experience and ultimate authority over the aircraft. Especially in this case as the FO was young and not very experienced. To substitute for the Captain's wrong data he can still refer to the standby instruments and the FO can call speed, altitude and pitch out. With the stab trim acting up and the struggle to keep it in the air you'd definitely want the more experienced cockpit crew member flying the aircraft.

Well, not necessarily.

The FO is qualified (and, arguably, with 300 hours probably much more current in instrument flying having just come out of a training system where they would have spent a lot of time doing exactly that than a Captain who may have x,000 hours but how many of those will have been recent hand-flying in IMC?) and perfectly competent to fly the aircraft.

There is a school of thought (and actually quite normal procedure in some airlines) that in non-normal situations the Captain should actually hand over the flying to the FO. This then frees up the Captain to manage the situation, run checklists, communicate with the cabin etc etc. For example, in this situation imagine if the Captain had handed over control to the FO:

- The FO would have had correct instrumentation (though remember that we are able to say that obviously the Captain's instrumentation was incorrect because with hindsight we know that to be the case -- at the time it will almost certainly not have been immediately apparent. As I say, if the stick shaker goes off is your first thought "oh, must be wrong"?)

- The FO could have concentrated on flying the aircraft and the more experienced Captain could have devoted his attention to diagnosing the problem and taking the appropriate actions

It is always tempting for a leader to dive in to action in a non-normal situation but often it is much better for the leader to stand back half a step and take a better overview of the situation...

[KevinAu 441]

4 minutes ago, threegreen said:

In an emergency like that it's always the Captain who's PF because of greater experience and ultimate authority over the aircraft. Especially in this case as the FO was young and not very experienced. To substitute for the Captain's wrong data he can still refer to the standby instruments and the FO can call speed, altitude and pitch out. With the stab trim acting up and the struggle to keep it in the air you'd definitely want the more experienced cockpit crew member flying the aircraft.

Not necessarily. We are trained to turn the plane over to the fo while the ca runs the procedures, manages the situation, coordinates assistance and makes decisions, unless there is an overriding reason for the ca to fly instead. In this case, if I was to survive the initial few minutes and get a handle on the situation, I would definitely turn the plane over to the fo who had good flight instruments and wasn’t holding onto a shaker. And in the instances where we got trim runaways in the sim, I don’t remember going against that convention even though the plane was hard to fly. The time I was an fo and had my windscreen shatter, I flew until the arrival where the captain did take control since I could see nothing out my window. When swa had the engine come apart and suck the pax out the window, the captain turned the flying over to the fo. Just because there is an emergency does not mean the captain takes over the flying. Both pilots are supposedly just as qualified as the other to fly the plane in any condition. But the captain is the one charged with making decisions, so the convention these days is for the fo to be the monkey flying so the captain can devote brainpower to being the human making decisions.

[Bobsk8 12,680]

12 hours ago, Christopher Low said:

We can argue all day about whether the pilots made mistakes or not, but (IMO) the most important spect of the two incidents is if the aircraft did something other than expected when they followed procedure. All the training in the world is not going to prepare you for that scenario. I can imagine that even the cool, trained brain of an airline pilot would start to panic in a situation like that

Just to get away with the mantra " Let's figure out how we can blame the pilots" for a moment, I think this video explains much of what is wrong in today's situation with Boeing and the FAA, 

 

[Garys 209]

Its a hard Mantra to break away from really.

The quick reaction of the crew to cutout the stabilizer before unloading the flight controls consequently caused everything that happen after that. I'm sorry but the crew is equally culpable for the end result and that is what we as the flying public expect skilled flight crews not to do.

Boeing certifying their own aircraft is also something that I hope comes to a complete stop. The whole situation is a mess.

Edited April 10, 2019 by Garys

[cowpatz 243]

Some of you armchair critics really have no idea about operating an aircraft. Especially one that is going wayward really fast with very confusing indications.

Please read this before you make anymore comments. It will help you understand the confusion and shear terror that would have taken place on that flight deck.
In fact don't just read it ....put yourself in the seat...you have just taken off on a routine flight, tracking the SID, retracting flap, accelerating, and then all hell breaks loose.

http://visualapproach.io/et302-even-without-answers-the-data-tells-a-story/

Further there is no evidence that either pilot turned the stab trim back on.....and if they did it was because they were desperate.

[KevinAu 441]

6 minutes ago, cowpatz said:

Some of you armchair critics really have no idea about operating an aircraft. Especially one that is going wayward really fast with very confusing indications.

Please read this before you make anymore comments. It will help you understand the confusion and shear terror that would have taken place on that flight deck.
In fact don't just read it ....put yourself in the seat...you have just taken off on a routine flight, tracking the SID, retracting flap, accelerating, and then all hell breaks loose.

http://visualapproach.io/et302-even-without-answers-the-data-tells-a-story/

Further there is no evidence that either pilot turned the stab trim back on.....and if they did it was because they were desperate.

1. I’ve got a wee bit of an idea how.

2. We’re not paid to be confused and terrified. The people in the back are counting on us not to be confused and terrified.

3. The trim wouldn’t have worked without someone turning it back on.

Edited April 10, 2019 by KevinAu

[G-RFRY 1,710]

Japan has just grounded all 12 of there F35s they have lost one at sea.

[Garys 209]

When we step onto a commercial airliner we are no longer armchair critics. I expect the aircraft to not go mechanical and I expect the flight crew to not turn a bad situation into a dire one if it does. As such I have just as much right to say how I feel about these events as everyone else. Instead of putting yourself in the pilots seat, instead put yourself in the passenger seat where 90% of us here would be sitting. It also seems to me that a lot of pilots putting the blame solely at Boeings feet fly with a stick instead of a yoke. 

Edited April 10, 2019 by Garys