China Eastern 737 down

Topics related to accidents, incidents & over due aircraft should be placed in this forum.

Moderators: sky's the limit, sepia, Sulako, lilfssister, North Shore

digits_
Top Poster
Top Poster
Posts: 5931
Joined: Mon Feb 14, 2011 2:26 am

Re: China Eastern 737 down

Post by digits_ »

Now the question becomes, who do we trust more to accurately report whatever is on the cvr: Boeing or China?
---------- ADS -----------
 
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
goldeneagle
Rank (9)
Rank (9)
Posts: 1177
Joined: Mon Jan 02, 2006 3:28 pm

Re: China Eastern 737 down

Post by goldeneagle »

digits_ wrote: Wed Mar 23, 2022 9:19 pm Now the question becomes, who do we trust more to accurately report whatever is on the cvr: Boeing or China?
This is a very high profile incident. When the device is opened there will be reps from the Chinese regulator, the American regulator, and Boeing present. There will likely be reps from the engine manufacturer and the device manufacturer as well.
---------- ADS -----------
 
Mick G
Rank 4
Rank 4
Posts: 254
Joined: Sun Feb 28, 2016 7:21 pm
Location: Alberta

Re: China Eastern 737 down

Post by Mick G »

Wonder if the pitot tube were blocked?
---------- ADS -----------
 
TeePeeCreeper
Rank (9)
Rank (9)
Posts: 1016
Joined: Sun Dec 21, 2008 12:25 pm
Location: in the bush

Re: China Eastern 737 down

Post by TeePeeCreeper »

Mick G wrote: Thu Mar 24, 2022 9:00 pm Wonder if the pitot tube were blocked?
By what? They were reportedly at cruise in VMC conditions…

I’ve unfortunately had both of mine blocked after encountering unforcasted severe icing. It was an “affair” down low… I highly doubt that this crew made it this far along their flight profile with a blocked system without saying a damn thing. Speaking of which… no distress call, zip, nada, niet. It’s boggling my mind!

TPC
---------- ADS -----------
 
Mick G
Rank 4
Rank 4
Posts: 254
Joined: Sun Feb 28, 2016 7:21 pm
Location: Alberta

Re: China Eastern 737 down

Post by Mick G »

TeePeeCreeper wrote: Thu Mar 24, 2022 9:45 pm
Mick G wrote: Thu Mar 24, 2022 9:00 pm Wonder if the pitot tube were blocked?
By what? They were reportedly at cruise in VMC conditions…

I’ve unfortunately had both of mine blocked after encountering unforcasted severe icing. It was an “affair” down low… I highly doubt that this crew made it this far along their flight profile with a blocked system without saying a damn thing. Speaking of which… no distress call, zip, nada, niet. It’s boggling my mind!

TPC
Yeah i know its unlikely, I'm just trying to rationalize what looks like an intentional act. If they were lower, one could surmise a similar incident like Atlas Air 3591 or pitot tube
---------- ADS -----------
 
flyndad
Rank 3
Rank 3
Posts: 102
Joined: Thu Nov 04, 2021 5:13 pm

Re: China Eastern 737 down

Post by flyndad »

The unfortunate reality of intentional acts are we end up with both cover-ups and blame. Egypt Air and Malaysian come to mind and it is important that the chain of evidence is maintained throughout. It would be more beneficial if a third party country is involved where it concerns both black boxes.
---------- ADS -----------
 
TheStig
Rank 8
Rank 8
Posts: 824
Joined: Thu Nov 10, 2011 12:34 pm

Re: China Eastern 737 down

Post by TheStig »

boeingboy wrote: Wed Mar 23, 2022 9:14 pm CVR has been found.

From Avherald...
The captain had accumulated 6,709 flight hours total, the first officer 31,769 flight hours, the second officer 556 hours, all of them in good family relations. The aircraft was in an airworthy condition, all maintenance had been done in strict compliance with regulations and requirements.
“All of them in good family relations” so I guess that rules out this being an intentional act…

Also, was the maintenance done in strict compliance with regulations and requirements with real or counterfeit parts?

Seems a little premature to be making either of those claims.
---------- ADS -----------
 
pelmet
Top Poster
Top Poster
Posts: 7138
Joined: Tue Jun 14, 2005 2:48 pm

Re: China Eastern 737 down

Post by pelmet »

Haven't read through this thread yet(just the one on PPrune), but I think this article says it all for this accident and so many more......

Clamour for China Eastern crash theories is at odds with reality
By Lewis Harper24 March 2022


Few incidents prompt greater focus on the airline industry than a fatal crash.

Following the tragic loss of a China Eastern Airlines Boeing 737-800 on Monday, the scrutiny – informed or otherwise – has been intense, in general reporting and particularly on social media.

The internet is awash with theories regarding the cause of the crash, notably including those carelessly based on imagery from a computer reconstruction of an incident that happened 25 years earlier.

During such times, the commentators worth listening to tend to be those urging people to wait for further evidence to emerge.

So far, aside from flight-tracking data, the few fresh details released via official channels include acknowledgements of failed attempts by air traffic control to contact the aircraft as the incident occurred and of the damaged cockpit voice recorder being recovered.

One certainty is that in China’s huge aviation market, the incident marks the first fatal crash since 2010.

And within the wider context of airline safety, the crash has occurred in an industry that has a remarkable safety record, as was reflected in IATA’s recent summary of 2021 data.

None of that is, of course, any comfort to those who have lost loved ones this week.

As ever, commercial’s aviation licence to connect the world is contingent on it doing everything within its power to establish why catastrophic incidents have occurred, before acting promptly on any recommendations. The first part of that process may take some time.

As investigators continue their work, many commentators will already be tired of having to point out that the crash is unrelated to the safety issues with the 737 Max programme. The requirement to do so undeniably reflects that the latter programme and Boeing’s reputation are still very much in the public consciousness, even as hundreds of Max jets fly without fanfare in markets around the world.

On the latter point, it is not unreasonable to question whether this week’s crash might further extend the long wait for Max jets to fly again in China, on the grounds of optics alone.
---------- ADS -----------
 
Last edited by pelmet on Fri Mar 25, 2022 9:25 pm, edited 1 time in total.
goldeneagle
Rank (9)
Rank (9)
Posts: 1177
Joined: Mon Jan 02, 2006 3:28 pm

Re: China Eastern 737 down

Post by goldeneagle »

Circling back to that adsb data, have a question for those a bit more 'in the know' on how the avionics work on the -800. Is the altitude reported on that adsb track coming from a pressure source, or from a gps source ?

After putting a bunch of thought into it, I have realized a few ways the apparent 'climb' could show up as simply bad data. If it's coming from a pressure source, and speeds were such that shock waves have developed, then there will be abnormal areas of high pressure. A scenario then that can product that trace, even without an actual climb, with high pressure behind a shock wave affecting a static source, it'll show a much more rapid descent than what was actually happening. As the aircraft hits thicker air below, some deceleration, shock wave dissipates, pressure drops, which will register as a climb if the data comes from a static pressure source.

If the data comes from a civilian gps source, they have a top end speed limit coded in, above which they report garbage data. This is an intentional thing to ensure 'off the shelf' gps equipment cant be used for targetting missles etc. If the aircraft was really in a vertical dive and approaching transonic or even supersonic speeds, then the data from a civilian gps cannot be relied on to be accurate, and in fact if it's is erronously reporting altitudes incorrectly the system designers will tell you 'working as intended'.

If indeed the aircraft basically did a power on vertical descent from 29,000 feet as suggested, it's quite possible, and actually realistic, for that adsb trace to be a huge big red herring.
---------- ADS -----------
 
Hugh Jasshole
Rank 2
Rank 2
Posts: 50
Joined: Thu Aug 01, 2013 11:21 pm

Re: China Eastern 737 down

Post by Hugh Jasshole »

I watched a YouTube video and the claim was that the ADSb speed is GPS ground speed. Therefore, if the plane is almost vertical, the ground speed will be WAY lower than the actual AS.
---------- ADS -----------
 
Pacqing
Rank 4
Rank 4
Posts: 232
Joined: Sat Nov 11, 2017 5:14 pm

Re: China Eastern 737 down

Post by Pacqing »

What maintenance issue or lack of could cause this? Has anyone here ever worked in maintenance in China. I would hope Boeing has tech reps on site with such a large fleet. I worked with a guy who did a contract there a few years ago and he said he sat in a class where the instructor gave incorrect info and even though the students knew it was wrong they would not speak up. Culture I guess. I'm wondering if this could still be the case and could it cause al the holes to line up.
---------- ADS -----------
 
digits_
Top Poster
Top Poster
Posts: 5931
Joined: Mon Feb 14, 2011 2:26 am

Re: China Eastern 737 down

Post by digits_ »

goldeneagle wrote: Fri Mar 25, 2022 10:44 am Circling back to that adsb data, have a question for those a bit more 'in the know' on how the avionics work on the -800. Is the altitude reported on that adsb track coming from a pressure source, or from a gps source ?

After putting a bunch of thought into it, I have realized a few ways the apparent 'climb' could show up as simply bad data. If it's coming from a pressure source, and speeds were such that shock waves have developed, then there will be abnormal areas of high pressure. A scenario then that can product that trace, even without an actual climb, with high pressure behind a shock wave affecting a static source, it'll show a much more rapid descent than what was actually happening. As the aircraft hits thicker air below, some deceleration, shock wave dissipates, pressure drops, which will register as a climb if the data comes from a static pressure source.

If the data comes from a civilian gps source, they have a top end speed limit coded in, above which they report garbage data. This is an intentional thing to ensure 'off the shelf' gps equipment cant be used for targetting missles etc. If the aircraft was really in a vertical dive and approaching transonic or even supersonic speeds, then the data from a civilian gps cannot be relied on to be accurate, and in fact if it's is erronously reporting altitudes incorrectly the system designers will tell you 'working as intended'.

If indeed the aircraft basically did a power on vertical descent from 29,000 feet as suggested, it's quite possible, and actually realistic, for that adsb trace to be a huge big red herring.
The military limitations supposedly only kick in above 1000 kts or FL 590 (source https://en.m.wikipedia.org/wiki/Coordin ... t_Controls)
---------- ADS -----------
 
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
boeingboy
Rank (9)
Rank (9)
Posts: 1507
Joined: Wed Mar 03, 2004 2:57 pm
Location: West coast

Re: China Eastern 737 down

Post by boeingboy »

How plausible is it that someone could bomb a Chinese airliner over mainland China? I have never flown there - but I would imagine it would be more difficult than other parts of the world. Don't think I've ever heard of that happening either.

We know part of the aircraft came off either causing the initial upset or happening very shortly after the initial upset. The aircraft seems to have spiraled down given the ADSB info and there are 2 crash sites about 245 meters apart. The 2 videos show a different crash - so I assuming that each video shows a different section of the aircraft - rather than 1 intact aircraft.

Something else puzzling is that the last ADSB contact and the 2 crash sites are about 2-3 km apart and in the opposite direction of the aircrafts flight path. (Crash is west of the last known ADSB position with the aircraft travelling eastbound)

CA.jpg
CA.jpg (47.37 KiB) Viewed 2906 times
china_eastern_b738_b-1791_guangzhou_220321_map1.jpg
china_eastern_b738_b-1791_guangzhou_220321_map1.jpg (86.88 KiB) Viewed 2909 times
ca2.jpg
ca2.jpg (309.92 KiB) Viewed 2901 times
---------- ADS -----------
 
goldeneagle
Rank (9)
Rank (9)
Posts: 1177
Joined: Mon Jan 02, 2006 3:28 pm

Re: China Eastern 737 down

Post by goldeneagle »

boeingboy wrote: Fri Mar 25, 2022 8:46 pm We know part of the aircraft came off either causing the initial upset or happening very shortly after the initial upset.
Have you a reference for that ?
---------- ADS -----------
 
User avatar
AirFrame
Rank 10
Rank 10
Posts: 2610
Joined: Sun Oct 11, 2009 10:27 pm
Location: Sidney, BC
Contact:

Re: China Eastern 737 down

Post by AirFrame »

goldeneagle wrote: Fri Mar 25, 2022 10:44 amCircling back to that adsb data, have a question for those a bit more 'in the know' on how the avionics work on the -800. Is the altitude reported on that adsb track coming from a pressure source, or from a gps source ?
Assuming ADS-B in airliners report the same as in GA aircraft, altitude is reported from pressure data, speed is reported from GPS.
---------- ADS -----------
 
User avatar
AirFrame
Rank 10
Rank 10
Posts: 2610
Joined: Sun Oct 11, 2009 10:27 pm
Location: Sidney, BC
Contact:

Re: China Eastern 737 down

Post by AirFrame »

boeingboy wrote: Fri Mar 25, 2022 8:46 pmWe know part of the aircraft came off either causing the initial upset or happening very shortly after the initial upset.
Reference?
The 2 videos show a different crash - so I assuming that each video shows a different section of the aircraft - rather than 1 intact aircraft.
I've only seen the video showing the fuselage heading straight in... Reference for a second video?
---------- ADS -----------
 
Donald
Rank 10
Rank 10
Posts: 2368
Joined: Mon Feb 16, 2004 8:34 am
Location: Canada

Re: China Eastern 737 down

Post by Donald »

goldeneagle wrote: Sat Mar 26, 2022 8:18 am
boeingboy wrote: Fri Mar 25, 2022 8:46 pm We know part of the aircraft came off either causing the initial upset or happening very shortly after the initial upset.
Have you a reference for that ?
Go to the av herald link. There was a piece of winglet found, as well as an "arc shaped" piece of wreckage, well away from the main wreckage.
---------- ADS -----------
 
boeingboy
Rank (9)
Rank (9)
Posts: 1507
Joined: Wed Mar 03, 2004 2:57 pm
Location: West coast

Re: China Eastern 737 down

Post by boeingboy »

AirFrame wrote: Sat Mar 26, 2022 8:43 am
boeingboy wrote: Fri Mar 25, 2022 8:46 pmWe know part of the aircraft came off either causing the initial upset or happening very shortly after the initial upset.
Reference?
The 2 videos show a different crash - so I assuming that each video shows a different section of the aircraft - rather than 1 intact aircraft.
I've only seen the video showing the fuselage heading straight in... Reference for a second video?
Parts departing:
https://avherald.com/h?article=4f64be2f&opt=0

On Mar 24th 2022 the CAAC reported in their 4th press conference, that a large piece of debris (1.3 meters by 0.1 meters) from the aircraft was found in farmland at Yatang Squad (coordinates N23.3111 E111.0002) in Siwang Village (coordinates N23.3054 E110.9711), about 12km west of the crash site and about 3.2km southeast of the last ADS-B position in cruise flight at 29100 feet MSL (it needs to be pointed out, we don't know whether this separated before or during the dive at this time).

On Mar 26th 2022 the CAAC reported in their 6th press conference, that the part found in Yatang was identified as trailing edge of a winglet of the crashed aircraft. Another piece of debris was found about 2.3km north of the debris at Yatang in Lixiu Village. The arc-shaped object is being examined and identified.

2nd video - taken from dashcam from a car on the adjacent highway :

https://twitter.com/SHeReAdYeVenTs/stat ... de%3Dfalse

https://www.reddit.com/r/interestingasf ... _by_china/


ca3.jpg
ca3.jpg (87.69 KiB) Viewed 2492 times
---------- ADS -----------
 
Last edited by boeingboy on Sat Mar 26, 2022 7:02 pm, edited 7 times in total.
boeingboy
Rank (9)
Rank (9)
Posts: 1507
Joined: Wed Mar 03, 2004 2:57 pm
Location: West coast

Re: China Eastern 737 down

Post by boeingboy »

2 crash sites plus the highway where the dash cam is seen in the second video...



crash site2.jpg
crash site2.jpg (89.99 KiB) Viewed 2482 times
china_eastern_b738_b-1791_guangzhou_220321_map2.jpg
china_eastern_b738_b-1791_guangzhou_220321_map2.jpg (97.3 KiB) Viewed 2482 times
---------- ADS -----------
 
boeingboy
Rank (9)
Rank (9)
Posts: 1507
Joined: Wed Mar 03, 2004 2:57 pm
Location: West coast

Re: China Eastern 737 down

Post by boeingboy »

Just in.....The second recorder (flight data recorder) has been found.
The device, found 1.5 metres (5 feet) beneath the surface of the slope, will be sent to Beijing for checks on Sunday, according to state media.

https://www.msn.com/en-ca/news/world/ch ... fad050ac7a
---------- ADS -----------
 
Post Reply

Return to “Accidents, Incidents & Overdue Aircraft”