China Eastern Airlines flight MU5735 737-800 Crash 17

[Eufalconimorph]

Avherald.

Reuters.

Dash cam footage showing crash angle.

Video of security camera video, straight on (angle of descent looks steeper than reality).

 

[Alistair_Heaton]

the flight data stuff is something like that with a stupid number of variables.

There is a cut down version called QFDR which the airline legally has to down load every 3 days which is used to monitor the pilots through a quality system.

The A220 if you bust an aircraft limitation automatically triggers a data dump. What's in it I have no clue. Also if a caution or warning is triggered it also triggers a data dump through the ACARS system. Its not unusual to turn up on stand and there to be 2 technicians vans sitting waiting for us and then after pax gone its announced aircraft grounded give us the techlog. The aircraft has sent the maint a problem in flight and not told the pilots because there is nothing we can do about it.

 

[dik]

maybe big, but not monumental unless the agency is against cloud storage... Can you have a device that automatically triggers cloud storage of all the data in the red 'black' box?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Alistair_Heaton]

no it starts at engine start and finishes at engine stop for the bulk of the aircraft data. Some of it for apu and power buses etc goes the the aircraft health management system which is a parallel system which focuses on the systems which is not included in the FDR data. But to be honest its not something a pilot needs to know anything about.

The heath management stuff records 10 times more stuff than the FDR. They know how often the toilet flushes, how often the door cycles. It times valves opening and condition monitoring etc etc.

This is on a new FBW A220 I really doubt the 737 NG or MAX have anything like this modern standard. I presume it just has the legal bare minimum number of variables and all the systems have a distributed data retention.

In fact Boeing have applied for a dispensation for the MAX 10 certification because it looks like the law brought into force after the MAX fiasco for certification will come into effect before they can complete the MAX 10. And its utterly impossible for it to meet modern safety standards. So if the FAA doesn't give them another 12 months then the max 10 is scrap. Some think that they won't complete in 12 months anyway.

 

[Alistair_Heaton]

The ACARS data stream is via a VHF link when the exceedance trigger does a data dump.

Others will have to tell you how much and how fast it can do that dump.

All I know is that these days the techs know what's happened before we are on the ground but the first thing they do it plug the laptop into the data bus in the cockpit and its not finished by the time we go 10 mins later. They have zero interest in what we think we saw.

 

[Alistair_Heaton]

But please note this is only valid for modern certified aircraft I would be extremely surprised bordering on gobsmacked if the 737 will have this capability. The systems are just not on a common data bus and half of them won't have a sensor on them because it would trigger recertification and if its not required they will be the same 1960 analogue sensor aka the 737 max AOA sensor which will be pumped through a ADC to some black box single channel processor chip with 50kb of RAM which will then if legislation requires will be sampled at the minimum data capture rate... Because that's what puts the money in the MBA's bonus packet every year.

 

[1503-44]

I'm not much on digital math, but isnt 33k variables, maybe 8 chr ea, 8 bits per chr, 5x/second ... 3600s/h = 38 GB/h ? Anyway, it's going to be a lot, even if it's 1/0

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[Alistair_Heaton]

I really don't have a clue of facts I just know its utterly colossal what the FBW machines store.

They do selectively dump when they transfer from buffer to recorded if nothing abnormal has happened. But if one of the triggers has occurred they dump everything.

There are different capture rates depending on variable and registry. Your going to have to wait until a real aero turns. Us stick monkeys really don't need to know to fly the contraption.

 

[TugboatEng]

Here is an article with some numbers.

https://www.aerospacemanufacturinga...past several years,as many as 25,000 sensors.

It says the engines sample at 5000hz. A 787 will generate 500GB of data in a flight. An A380 can have up to 25k sensors.

 

[verymadmac]

My gut feel is its something mechanical that's gone twang.

But it could be the crew stalled it but that's extremely unlikely at 29 000 ft the window between over speed and stall is colossal that low. Your not even limited by mach numbers at that alt.

Given it was largely intact & the angle, unfortunately a deliberate dive has to be high on the cards.

29,000 ft isn't really that high when it comes to Oxygen issues, that altitude will still kill you but it 40,000 ft should be survivable. Unless it was depressurization plus covid related loss of lung capacity in the pilots.

Maintenance is always interesting, I seen the results of crap heavy checks on aircraft in the USA & Europe (how do you sign off a gear inspections with no jacks on site), nothing like using the lowest bidder. I know Qantas has had issues in the PRC when a 747 heavy check got too hard and the Chinese MRO just push it out on to the hardstand to maintain their schedule, & Qantas had to fly their guys up to get it to ferry flight standard to bring it back to OZ to complete the work.

 

[TugboatEng]

It is possible to shake the tail off a plane, even without manufacturing or maintenance defects.

https://en.m.wikipedia.org/wiki/American_Airlines_Flight_587

 

[RedSnake]

Given it was largely intact & the angle, unfortunately a deliberate dive has to be high on the cards.

Since the steep dive started at the same point as a normal descent would have started it seems more unlikely that it was deliberate why wait to that exact point to do it.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[Nukeman948]

...why wait to that exact point to do it.

Stop thinking like a non-suicidal person. If you just want to commit suicide, there is no reason to take innocent people with you. But if you want to also damage the airline industry and the aircraft manufacturer while not harming your family's reputation or their ability to collect your life insurance, then it seems to make a bit more sense to a twisted mind.

[sub]Time to make some plans...
[/sub]​

 

[Debirlfan]

The problem I have with the suicide theory is that the pilot wasn't alone in the cockpit. There was a copilot and a third pilot who apparently was some sort of trainee or observer. Given that it was time to start their descent, it's highly likely they would have all been in the cockpit. So the pilot decides to crash the plane, and the other two just sit there? Surely one would attempt to take control while the other overpowered the pilot?

I believe I've seen some comments that the aircraft also veered to the side when it started dropping? If so - could the pilot have been making an abrupt evasive action and lost control or over stressed parts of the tail? Perhaps evading a drone or even a formation of birds? (Yes, there are birds in Asia that fly at 20,000 ft., I checked.)

 

[Sym P. le]

The .kmz file that I uploaded earlier plots the flightradar24 data and shows that the flight path was no longer direct upon and after the initial decent. Unfortunately there is a data point missing between the last known straight and level and the first deviant points.

 

[Sym P. le]

From Getty Images I can now see that the hillside north of the crash site is scorched so I've deleted my previous post being skeptical of the extent of fire.

 

[Tomfh]

The problem I have with the suicide theory is that the pilot wasn't alone in the cockpit

Presumably you’d incapacitate the others first.

 

[Sym P. le]

Twitter "Aviation expert David Learmount explained to @CGTNEurope ..." argues for emergency decent.

 

[Sym P. le]

20 g's pulling out of the dive sounds rather extreme. I wouldn't doubt that the aircraft could handle it but I doubt that the pilots could hold onto the controls. No experience, just conjecture.

 

[hokie66]

And to think, I just learned in another thread on the site that photos from 'Getty Images' are stock photos, not to be taken as current. How do we know that the photo of that area is of the crash site?

 

[Sym P. le]

Someone linked to that photo on twitter. That's how we know Otherwise you are correct. I tried to search Getty and came up empty.