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China Eastern 737-800 MU5735 accident March 2022

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China Eastern 737-800 MU5735 accident March 2022

Old 20th May 2022, 11:47
  #521 (permalink)  
 
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Originally Posted by phylosocopter View Post
But if for some reason they were only seeing blue that would go some way to explaining events . We do not know. How about we wait for more facts.
What, on all three displays - both PFDs and the Standby ? Highly unlikely that all three would simultaneously display massive pitch-up.

Mind, you that Swedish CRJ did a similar thing when only the Captain's AI display went wrong.

From what FWRWATPLX2 posts - very worrying and concerning - it seems that we might never know the truth?
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Old 20th May 2022, 11:59
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This accident is more like a problem of protocol and sharing results with the public it seems.
We have the trajectory, no obvious technical problems with the accident aircraft and no current change requirements for China's active fleet, all pointing in one direction...
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Old 20th May 2022, 14:24
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Originally Posted by EDLB View Post
Simple answer. Only brown color on the PFD.
Originally Posted by phylosocopter View Post
But if for some reason they were only seeing blue that would go some way to explaining events . We do not know. How about we wait for more facts.
Originally Posted by Uplinker View Post
What, on all three displays - both PFDs and the Standby ? Highly unlikely that all three would simultaneously display massive pitch-up.

Mind, you that Swedish CRJ did a similar thing when only the Captain's AI display went wrong.

From what FWRWATPLX2 posts - very worrying and concerning - it seems that we might never know the truth?
Sure, daylight and pretty clear sky, as it seems.
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Old 20th May 2022, 14:28
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Originally Posted by jolihokistix View Post
Scenario 2/20.

If I was senior (and bitter) enough, maybe I could just request everyone else out of the cockpit, apart from the one at the controls. From there it’s my field of play…
Originally Posted by FlightDetent View Post
Not allowed and its and eerie request. But waiting for the right moment when PIC goes to toilet before TOD...
​​​​​​... and the cadet would not take the vacant chair but stay on the jump seat out of courtesy.
​​​​​
With such a scenario, there would have been no successful recovery, halfway down.
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Old 20th May 2022, 14:47
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Originally Posted by Stick Flying View Post
But your "bet" is on trim isn't it? If there were no defects currently being investigated, either it wasn't trim or it was forward trim with neutral or forward control input. Surely this type of event couldn't happen with any crew that were monitoring the flight path. And I can't think of many instances where a yoke input could be achieved without at least some form of pilot input (deliberate or accidental).

I have an open mind on this event. What we currently have is a leak from some party which in my mind has no credibility guarantee. Until we get something on formal lines I'd say there are many possible scenarios. The sooner this can be put to bed the better in my opinion.
Trim: I don't want to rule out the "control" through trim. The leaked message is just too cryptic to let it have been a "normal" yoke control of the airplane.

Investigation: There is probably not that much physically left to investigate, given the airplane is largely shattered in small pieces. So, it's largely only FDR/CVR.

What I am suggesting is, there are more tech ways to move the pitch control surfaces, than only the yoke and trim switches itself. Having an open mind to these aspects might be useful, instead of diving onto a suicide scenario.

For example, remember the recent fight between FAA and Boing about the YES/NO cable rerouting, because short-circuits were presumed to be able to cause the trim motor to move, without the trim switches being activated (Or the trim-disable switches being effective). We also know, that manual trim with the trim wheel is only theoretically possible. And we also know, stopping a run-away trim by holding the trim wheel will also be challenging.

There are simply too many fuzzy aspects, not really fitting an upfront suicide scenario.
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Old 20th May 2022, 14:57
  #526 (permalink)  
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Quick comments ; on the suicide hypothesis, nothing concrete so far, so let's give it a bit of time until the CVR analysis either confirms or infirm that. Would it be only out of respect for the pilots and the victims families.

FWRWATPLX2 :
Andreas Lubitz, (GermanWings) passed the DLR, which has a high failure rate.
Andreas Lubitz was a highly intelligent young man who knew all the answers to give and which box to tick before joining, he became later totally obsessed with losing his licence, and flying was his only passion and that drove him totally outside the edge. The very sad thing is that everyone around him knew he had lost it, his girl friend, his parents , his brother , his psychiatrist and most of the dozen of doctors he consulted in the 6 months before his act. Sadly none of them could prevent him for reporting sick , even less in quitting the job. . This loophole is still there , in Germany at least .Mental illness is a huge issue and many companies do not know how to deal with it.

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Old 20th May 2022, 15:14
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He was ill and this was known. This is why he had to interrupt his flight training and pause. He got cleared to return after medical examination and by special permit. Only then things went out of control.

Last edited by Less Hair; 20th May 2022 at 15:49.
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Old 20th May 2022, 15:31
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Originally Posted by WideScreen View Post
Trim: I don't want to rule out the "control" through trim. The leaked message is just too cryptic to let it have been a "normal" yoke control of the airplane.

Investigation: There is probably not that much physically left to investigate, given the airplane is largely shattered in small pieces. So, it's largely only FDR/CVR.

What I am suggesting is, there are more tech ways to move the pitch control surfaces, than only the yoke and trim switches itself. Having an open mind to these aspects might be useful, instead of diving onto a suicide scenario.
You are missing the point. The leak suggested the "plane did what it was told to by someone in the cockpit". That would rule out runaway trim in my opinion. I will concede, the leak is no more reliable than a paper tissue condom.
Either way, runaway trim has a memory item drill. Given the demise of the Max, I'd have thought any Boeing crews would be pretty hot on that.
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Old 21st May 2022, 02:41
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Originally Posted by Uplinker View Post
What, on all three displays - both PFDs and the Standby ? Highly unlikely that all three would simultaneously display massive pitch-up.

Mind, you that Swedish CRJ did a similar thing when only the Captain's AI display went wrong.

From what FWRWATPLX2 posts - very worrying and concerning - it seems that we might never know the truth?
My point was that a CFIT might be the result of a loss of situational awareness (for whatever reason) rather than criminal intent.
I also wonder if perhaps the initial descent might be because of a decompression event or other emergency (or the pilot believed there was one) and then somehow the leveling out from that manoeuver was botched. This scenario could fit both the flight profile and the "pilot inputs" info.
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Old 21st May 2022, 03:42
  #530 (permalink)  
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Originally Posted by phylosocopter View Post
My point was that a CFIT might be the result of a loss of situational awareness (for whatever reason) rather than criminal intent.
I also wonder if perhaps the initial descent might be because of a decompression event or other emergency (or the pilot believed there was one) and then somehow the leveling out from that manoeuver was botched. This scenario could fit both the flight profile and the "pilot inputs" info.
The actual cause of the accident will be discernable from the flight data recorder parameters of control column position and elevator and stabilizer position v aircraft flight path.
ICAO Annex 6 Part I, App 8 states the basic requirements for the FDR, it is mandatory to have had both the primary flight control surface and the primary flight control pilot inputs. Force inputs are not mandatory unless they are also displayed to the pilot in some form that they are not on the B737, however, the DFDAU may still be recording that data and providing it to the DFDR. (have looked at both outputs, with and without, and also separately recorded the forces by a tap from the databus for test purposes (429), which was not recorded by the DFDR (717), but was being measured). The integrity of the control run can be ascertained from the position data of the control input and the control position, and that will tell immediately whether the flight path was a deliberate action or not. If CAAC doesn't release the data, then it will be up to the next of kin to take action to subpoena the data. CAAC accident reports alone have questionable value beyond any data they provide; wasted lots of time with the lunacy that passes for analysis in their reports. Great food, good beer, accident reports not so much.
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Old 21st May 2022, 04:11
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ATC Watcher wrote:
The very sad thing is that everyone around him knew he had lost it, his girl friend, his parents , his brother , his psychiatrist and most of the dozen of doctors he consulted in the 6 months before his act. Sadly none of them could prevent him for reporting sick , even less in quitting the job

Anyone one of them so close to Andreas could have easily picked up the telephone and called airline management or Luftfahrt-Bundesamt. That is all it would have taken. Every Aviation Regulator, around the world has a Safety Hotline.
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Old 21st May 2022, 06:13
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@ATC Watcher; where did you get this information from? It makes it sound like it was obvious as daylight and if so then those around him should bear some responsibility. Bearing in mind his parents disagree with the findings of the investigation and claim it wasn't suicide - they can't be included in your statement.

When a person commits suicide part of the pain of those left behind is the feeling that they should have seen it coming and should have done something - they feel in some way responsible. But the sad reality is that if it was that obvious then either someone would have done something to prevent it or they are complicit in the process (in general).
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Old 21st May 2022, 09:07
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Originally Posted by Stick Flying View Post
You are missing the point. The leak suggested the "plane did what it was told to by someone in the cockpit". That would rule out runaway trim in my opinion. I will concede, the leak is no more reliable than a paper tissue condom.
Either way, runaway trim has a memory item drill. Given the demise of the Max, I'd have thought any Boeing crews would be pretty hot on that.
Maybe, I am missing the point less than you think. Read this post:

“The plane did what we read back from what the sensors of the cockpit flight controls registered on the FDR."

Or so to say, don't blindly trust sensors / sensor registrations, when things did go haywire. A sensor could register trim switch activation, whereas the factual situation might be a short circuit, simulating the trim switch activation.

And, of course, runaway trims are a hot item for Boing 737 crews, though we also know, that "the manual trim wheel is there because of regulations", "manually stopping that trim wheel is quite a challenge to put it mildly" and "manually trimming using the trim wheel is a demand that largely only works during certification demonstration" (and not, when things go haywire).

We do have the situation of a complete recovery, as well an initial action to return to the original FL and then, things go haywire again. All accompanied by obvious attempts to "stay on course in a turbulent handling situation". This is not something that much compatible with a suicide attempt.
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Old 21st May 2022, 09:10
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Originally Posted by phylosocopter View Post
My point was that a CFIT might be the result of a loss of situational awareness (for whatever reason) rather than criminal intent.
I also wonder if perhaps the initial descent might be because of a decompression event or other emergency (or the pilot believed there was one) and then somehow the leveling out from that manoeuver was botched. This scenario could fit both the flight profile and the "pilot inputs" info.
Decompression event and then nose over into a >45 degrees dive ? Hmmmm.
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Old 21st May 2022, 09:22
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Originally Posted by BoeingDriver99 View Post
@ATC Watcher; where did you get this information from? It makes it sound like it was obvious as daylight and if so then those around him should bear some responsibility. Bearing in mind his parents disagree with the findings of the investigation and claim it wasn't suicide - they can't be included in your statement.

When a person commits suicide part of the pain of those left behind is the feeling that they should have seen it coming and should have done something - they feel in some way responsible. But the sad reality is that if it was that obvious then either someone would have done something to prevent it or they are complicit in the process (in general).
The issue with suicidal people is, they often live a life to socially please other people. With the consequence, those people become very hesitating to report that person to the authorities, etc.
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Old 21st May 2022, 09:31
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Originally Posted by FWRWATPLX2 View Post
ATC Watcher wrote:
Anyone one of them so close to Andreas could have easily picked up the telephone and called airline management or Luftfahrt-Bundesamt. That is all it would have taken. Every Aviation Regulator, around the world has a Safety Hotline.
Yes Capt Hindsight at work again . For the direct family as Boeing driver 99 said, they are in complete denial of the suicide version , embarking in the cockpit fumes theory , they certainly would not have called the airline or the LBA .
But they all knew he was not mentally well and should not have been flying , That was my point here.
. As to the medical staff all of them the law in Germany is absolutely strict , total confidentiality is mandatory . You could loose your practice if you called the authorities. These strict laws date back from 1945-46 following the Nazi times where mentally sick people were denounced by their doctors and ended up being euthanatized . Even after the event , most of those doctors do not feel guilty , they followed the law they say. I am glad I am not in their shoes .

Boeing Driver 99 :
ATC Watcher; where did you get this information from? It makes it sound like it was obvious as daylight and if so then those around him should bear some responsibility
How do I know the details? Too long to explain and not for internet, send me a PM if you want. Just to clarify a point : it was not obvious at all to anyone that he would commit this mass murder , or even that he would commit suicide , as far as I know no-one predicted that , but those I mentioned that they knew he was not mentally well lately, totally obsessed about losing his license, did not sleep , and should not definitively have been flying , Many of the 40 or so doctors he consulted in the last months gave him papers to stay at home and not work, but he disregarded them ( some were found in his home afterwards) and he continued to fly. As to who should bear responsibility ? I do not want to be entering that debate, read again the way I phrased my earlier post ..

As an incident investigator said ; what can we do to prevent this from happening again ? and can it happen again? . I do not have an answer to the first question (,the F/A in cockpit was a knee jerk reaction that did not last long) but to the second question : sadly , it is a yes.
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Old 21st May 2022, 11:21
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Originally Posted by WideScreen View Post
We do have the situation of a complete recovery, as well an initial action to return to the original FL and then, things go haywire again. All accompanied by obvious attempts to "stay on course in a turbulent handling situation". This is not something that much compatible with a suicide attempt.
You'd rather interpret the 'limited use' Flight Radar information as indicating 'a complete recovery'. That's quite a bold assumption to make. That event (the reduction in descent and initial climb) could quite easily have been some form of oscillation due to the dynamic forces (completely outside the realms of any tested envelope) that lead to a further structural failure. Or a structural failure that then lead to an oscillation returning to the original steep descent profile.

All I know is the aircraft entered a quite extreme profile. The information in the open domain at present indicates no conclusive explanation as to why. The investigation team may have a lead on the causes. A 'supposed' insider thinks the team know the aircraft behaved 'as commanded'. I don't personally think that insider leak holds any weight. I still think there are many possible causes, and yes, suicide could be plausible in my opinion. But so could aircraft malfunction or pilot error.
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Old 21st May 2022, 13:40
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Originally Posted by MikeSnow View Post
Wait, what? Speed is relative. As a result, kinetic energy is relative as well. Let's say you are sitting down in a train moving at a constant speed of 100 km/h relative to the ground, in a straight line. You as a passenger would have zero kinetic energy relative to the train frame of reference. And if the train wouldn't have any windows (and assuming you can't rely on noise either), you wouldn't even be able to tell if the train is stationary or is moving.

Now imagine you have a small drone, and you fly it inside that train. Again, it would be irrelevant if the train were moving at 100km/h or 200km/h relative to the ground, or if it were stationary. It would have no effect on the flight of the drone inside the train, and the G forces and aerodynamic effects it experiences.
Kinetic energy (and potential energy too) values are relative to the frame of reference you choose, however changes in kinetic energy during a collision are not. No matter which inertial frame of reference you will compute the collision in, the dissipated energy during the collision will always be 1/2*m*v^2.

For example if you consider the frame of the Earth, the initial energy is 1/2*m*v^2, final energy is zero, so energy dissipated is 1/2*m*v^2. If you consider the frame going at the same speed as the airplane, the initial kinetic energy is that of the Earth, and that kinetic energy becomes slightly less after the collision due to the impact (and small change of momentum of the Earth). The change is still 1/2*m*v^2
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Old 23rd May 2022, 18:31
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Originally Posted by tdracer View Post
The yoke forces are on the FDR - so it would be trivial to differentiate between pilot yoke inputs and a trim failure.
I know people who were directly involved in the Egypt Air investigation. The Egyptians never agreed with a pilot deliberate act, but among the investigators on this side of the pond, there was zero doubt.

It's rather well documented that people that are suicidal generally don't account for how their actions will affect other, uninvolved people (e.g. the passengers). Hence someone who decides to commit suicide by suddenly turning their car into on-coming traffic at high speed won't consider the impact of the young family occupants of the oncoming car.
Good point. Real outliers though these events in the air in any case...
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Old 24th May 2022, 00:44
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Im not sure if you have seen this video as it was uploaded to youtube 6 days ago but gives an interesting perspective...

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