China Eastern 737-800 MU5735 accident March 2022

[PJ2]

Originally Posted by Teddy Robinson

An intermediate report will be forthcoming within 30 days.
This has already been stated, and is the industry norm.

TR

...and there are no directives requiring early attention or urgent action on the part of B737 operators

[procede]

Originally Posted by Fonsini

If it was the Captain I’m sure that he could have found a reason to get them both out of the cockpit.

If it was anyone that committed suicide, it was the captain demoted to first officer.

[Organfreak]

I know that it's happened before, but any pilot who deliberately crashes his plane is also that very rare bird, a mass murderer.

[sSquares]

Originally Posted by Willstone

Squares, by cracked silicone do you mean the case or the die itself ?
If the case is cracked you can " decap " the dies from the case an transplant it
if it's cracked thru the die, then yes, game over.

The case is not silicon.

[WideScreen]

Originally Posted by Fonsini

If it was the Captain I’m sure that he could have found a reason to get them both out of the cockpit.

With only one person in the Cockpit, a suicide mission would not have had a successful (!) recovery halfway down to the ground.

[WideScreen]

Originally Posted by PJ2

...and there are no directives requiring early attention or urgent action on the part of B737 operators

For a directive, it would need an understanding of what happened and why it happened. For something happening on automation, that might need some time to figure out.

[Majorbyte]

Originally Posted by procede

Suicide with two other (much younger and fitter) pilots in the cockpit seems a bit unlikely to me.

really? it would take just a few moments, very little two 'fitter' pilots could do to stop it.

[mrdeux]

Originally Posted by vilas

Airbus cannot be put in attitude beyond -15° pitch. So no question of vertical dive. It was just a planned descent.

Of course it can. Just not in normal law.

[ivorget]

From Chinese TV channel CGTN on twitter today: (can't post link yet)

China denied rumors the MU5735 flight co-pilot is to blame for the crash, an official with the Civil Aviation Administration of China said at a news conference on Monday, adding those who spread rumors would be held accountable.

[PJ2]

Originally Posted by WideScreen

For a directive, it would need an understanding of what happened and why it happened. For something happening on automation, that might need some time to figure out.

Yes, understand that, thanks. Likely you know this, but sometimes in the course of early investigation, the DFDR may reveal something that could be of an immediate airworthiness concern. If readable or partially-so, I suspect by this time they may have an inkling of what happened and that it is, again likely, that it is not a type or fleet-wide matter. Also, I am taking into account who is in charge of the investigation in terms of the relative silence but the Chinese have indicated a 30-day report will be issued. That nothing by way of implementable procedure or technical change has been issued may be construed as a positive sign. Just grasping at straws like everyone else, believing that, "no news is 'good' news", I suppose.

[WideScreen]

Originally Posted by PJ2

Yes, understand that, thanks. Likely you know this, but sometimes in the course of early investigation, the DFDR may reveal something that could be of an immediate airworthiness concern. If readable or partially-so, I suspect by this time they may have an inkling of what happened and that it is, again likely, that it is not a type or fleet-wide matter. Also, I am taking into account who is in charge of the investigation in terms of the relative silence but the Chinese have indicated a 30-day report will be issued. That nothing by way of implementable procedure or technical change has been issued may be construed as a positive sign. Just grasping at straws like everyone else, believing that, "no news is 'good' news", I suppose.

Yep, an initial pretty plausible indication of what has happened, may trigger these early notifications, etc.

For now, we do have the situation the MU B737 fleet is still not returned to service. Suggesting, IF the CVR is indeed read out, the cause of this tragedy is not a deliberate human aspect, but more technical (weather and all kinds of other fantasies can be ruled out, I think).

TBH, I don't expect China to release anything from the CVR. China does have stringent privacy regulations (effectively, though, unless when the state itself is involved).

So, yeah, for now, we need to wait a couple of days. If no further notices are released, either the FDR can not be read, or this incident is not a copy cat of earlier incidents with a recognizable cause.

[silverelise]

Originally Posted by WideScreen

For now, we do have the situation the MU B737 fleet is still not returned to service.

Is that confirmed? FR appears to show MU 737s operating flights today.

[WideScreen]

Originally Posted by silverelise

Is that confirmed? FR appears to show MU 737s operating flights today.

While preparing my post about this, I checked around 20 frames (the newer ones) and none of these did fly in April. Checking again for you, now for nearly all, none of these did fly in April. All B737-800, the crashed version.

Checking for MU B737-700, you can see, these do fly (regularly), so I assume, this is what you saw.

[SATCOS WHIPPING BOY]

Originally Posted by WideScreen

With only one person in the Cockpit, a suicide mission would not have had a successful (!) recovery halfway down to the ground.

Partial recovery or a glitch in pressure data implying a temporary climb?

My thoughts are it was plummeting, and the FR data shows a drop in pressure rather than a physical climb. It's a long time since I did any altimetry but isn't the data fed by a static vent? Orient the aircraft body so that vent is in a low pressure air-flow (rolling and falling) and you get the apparent increase in altitude. ???

[WideScreen]

Originally Posted by SATCOS WHIPPING BOY

Partial recovery or a glitch in pressure data implying a temporary climb?

My thoughts are it was plummeting, and the FR data shows a drop in pressure rather than a physical climb. It's a long time since I did any altimetry but isn't the data fed by a static vent? Orient the aircraft body so that vent is in a low pressure air-flow (rolling and falling) and you get the apparent increase in altitude. ???

By wobbling around the aircraft nose, you can get some variations in pressure indication, though not that much as the FR24 data shows. If your theory would be valid, the wobbling would be able to distort the altitude measuring in the 5000-th feet, and that, during a steep decent. Also, when the nose stops wobbling, there is no catch-up visible in the FR24 data, so no sudden discontinuity, graphically showing a drop of 10000 feet (in the end, the recording roughly stops at terrain height). Just make a altitude graph yourself and you'll see, it's all pretty smooth. I think, theory busted.

Oh, and at those speeds, don't wobble the nose around to much, otherwise you may loose your tail-end, if not, even shred the aircraft.

[SATCOS WHIPPING BOY]

Thanks Widescreen. I take your point about the no catch up; just musing that a 1200ft gain is roughly a 40millibar drop in pressure.

Guess we'll just have to see what the end report has to say.

[grizzled]

Originally Posted by WideScreen

For a directive, it would need an understanding of what happened and why it happened. For something happening on automation, that might need some time to figure out.

WideScreen (and others that are fairly new to pprune)... With all due respect, you may want to click on a poster's public profile before you reply to one of their posts. And perhaps even look at some of their inputs to previous accident threads. To put it more simply, telling PJ2 what is needed for a directive to be issued is like telling a fish how to swim...

Cheers!

[AAKEE]

Originally Posted by WideScreen

Just make a altitude graph yourself and you'll see, it's all pretty smooth. I think, theory busted.

Oh, and at those speeds, don't wobble the nose around to much, otherwise you may loose your tail-end, if not, even shred the aircraft.

Yes. Even better than plotting a 2D graph is to use google earth or similar to make a 3D graph from the granular data. It is very informative.

[WideScreen]

Originally Posted by AAKEE

Yes. Even better than plotting a 2D graph is to use google earth or similar to make a 3D graph from the granular data. It is very informative.

Yep Google Earth is very valuable for the impression, but less for the analytics. Plotting a cloud of dots in just 2D in LibreOffice or so, gives the analytics part. Just take care to handle the time axis properly, and you see many more aspects than in a fancy Google 3D view.

For example: Data points like the Long/Lat give a nice straight line (especially for the first half of the down to earth trajectory) with just one small "S-curve" in it. Practically suggesting, the chance, there are 360's involved is pretty low. And, these data points being subject to aliasing with a max cycle of 30 seconds based on a 50+ ton passenger aircraft movements, is also quite unlikely.

[WideScreen]

Originally Posted by grizzled

WideScreen (and others that are fairly new to pprune)... With all due respect, you may want to click on a poster's public profile before you reply to one of their posts. And perhaps even look at some of their inputs to previous accident threads. To put it more simply, telling PJ2 what is needed for a directive to be issued is like telling a fish how to swim...

Cheers!

Maybe, I am less "new" to PP, than you assume. Think about 15+ years of lurking, before signing up and even then, not posting. Postings from PJ2, tdracer and several others are very interesting to read, so to say.

Oh, cheers (although, I don't drink myself).