China Eastern flight MU5735 crashes, 132 people were on board | Hacker News Reader

China Eastern flight MU5735 crashes, 132 people were on board

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Flightradar24 of the flight in question: https://www.flightradar24.com/data/aircraft/b-1791#2b367bc1

Purported footage at the crash site:

https://twitter.com/BNONews/status/1505829095204085760

https://twitter.com/ChinaAvReview/status/1505815956001501184

https://twitter.com/TheLegateIN/status/1505820283734994947

Is there a Twitter client/URL without replies or comments?

The ratio of users who jump immediately to ill-founded conspiracies or equally useless/malignant/ideological commentary is astounding to me. I don't want to see/hear/know their thoughts---online or in person.

I know it's not what you are looking for, but I can only tolerate Twitter with this https://nitter.net/about

A local news aggregator posted an election announcement this week in my state. No real bias, just the news that the election had been called for one party. Zero nuance in the comments; it was immediately riled up comments at either extreme of the spectrum. I can't imagine what this does mentally to people who read such an unfiltered firehose day after day.

replace twitter.com in URL with nitter.net for cleaner layout and easier to ignore comments

Twitterific (iOS) hides comments by default. TweetDeck (desktop) does the same.

TweetBot

Must have been horrific and sudden. Lost 26,000 feet in 3 minutes.

Alleged footage of the crash shows the plane dropping from the sky like a rock: https://twitter.com/aviationbrk/status/1505835466943352836

That matches the flight data posted from mlex reference:

Everything looks ok until:

6:19 AM UTC with the flight at 29100 ft (aprox 9 Km)

as of

6:22 AM UTC it's already at 9.000 ft (aprox 3 Km) dropping at vertical speed of -6,016 fpm

Excluding Terrorism, probably catastrophic Horizontal Stabilizer failure due to incorrect maintenance procedures.

Edit: Data available from past flights, shows this specific airplane in almost constant daily use, since at least Nov 2021. So it does not look like this was a flight after coming out of any recent major maintenance event.

If there is a lesson from the Boeing Max debacle, it is don't jump to conclusion of "incorrect maintenance procedures" like what Boeing did after the first crash with the Indonesian airline.

A lot of possibilities like Human/Pilot error, Equipment failure, Engineering design flaw, Freak bird collision accident, etc..

I agree with you. Since this is not a MAX just the most likely to cause this vertical drop. But yes, you are correct, lots of other causes need to be considered.

They didn't jump to that conclusion. They almost immediately knew it was MCAS but blamed the Indonesians anyway as a distraction.

Source: the recent documentary that came out

Jumping to conclusions is one thing, deliberate disinformation is another.

> probably catastrophic Horizontal Stabilizer failure due to incorrect maintenance procedures.

That is highly speculative at this point, this airline has a very good safety record.

Speculative yes. Highly speculative maybe not as much. You need to explain a 20,000 feet vertical drop in less than 2 min. Might not be the fault of the airline. Could be Boeing unclear instructions or a Supplier providing a faulty piece.

I bet that kind of drop will inevitably exceed the Vne because this plane does not have adequate speed brakes for this kind of maneuver (and why would it). I'm surprised it was still even intact when it hit the ground but according to the dash cam videos it was.

But I also think there's many things that can cause this. A terrorist taking over, the FBW system seriously messing up.

Anyway the investigation will tell us. Maybe soon because the black boxes won't be far away.

Not sure if they black boxes survive this type of drop. On the Air Lauda crash one could not be recovered.

Good point. This was really extreme. I hope for the families that they will be found and everyone will get closure soon.

Not such a good point, given that one indeed survived, and that in that particular case it wasn't the impact that destroyed the other one but the post crash fire.

Black Boxes are designed to stand 3,400 Gs what is about 300 Mph. Maybe the airplane did hit the ground at close to those speeds.

And the fact that the second one did not survive the crash due to fire, shows they are not indestructible. Fire is actually what they are supposed to survive for at least 1 hour.

This is a very simplistic view of an airplane crash. The whole airplane is the crumple zone for the black boxes mounted in the tail of the aircraft, that's for a pretty good reason so there goes one assumption, it's not like they are in the nose. And for another, those black boxes that were lost usually were lost either because the whole airplane was lost or because of the post impact fire.

There are some instances of flight data recorders and cockpit voice recorders that were destroyed but not a whole lot of those. That said, this was an exceptionally violent impact and it remains to be seen if there is anything usable.

But - again - speculation is utterly pointless there is simply no information to go on other than the angle and speed of impact, which definitely isn't giving hope, but it doesn't rule anything out either. So let's just be patient until there is actual data. Nobody ever said that black boxes are indestructible.

> Could be Boeing unclear instructions or a Supplier providing a faulty piece.

What is it with the senseless speculation?

Saying it's "probably" anything based off of two lines of text (even with a correlating video) is ridiculous irresponsible, and will almost always be wrong. Not to mention the fact there are a whole host of things that can cause a 6kfpm descent, both controlled and uncontrolled, that are neither terrorism nor the horizontal stabilizer.

>Saying it's "probably" anything based off of two lines of text (even with a correlating video) is ridiculous irresponsible

And as long as the number in the corner keeps getting bigger people will keep doing it.

You get what you incentivize. The purpose of a system is what it does.

I already acknowledged this was a speculative line of thought. Don't think any air crash investigators are looking into a nobody on the internet for accident clues, so it's a kind of very limited irresponsibility.

However there are actually not that many causes, that could explain the vertical drop either than, and in order of decreasing probability:

- Suicide/Terrorism

- A Jackscrew Mechanism Failure: https://www.wikiwand.com/en/Jackscrew

- Accidental Deployment of the Reverse Thrusters.

The accidental deployment of the reverse thrusters, is something that requires multiple mechanical failures, is not supposed to happen but Boeing already has a past history with it, although on a different model. The Niki Lauda/Boeing controversy.

"What if the reversers OPEN in flight?!"

Video at correct time: https://youtu.be/OguKthkuaT4?t=1026

If the reversers open, wouldn't just shutting down the engines lead to a better scenario than this? I recall a 737 gliding too a nearby airport in Canada when it ran out of fuel.

I suppose it depends on whether the crew would have been aware of it.

It all happened in less than 2 minutes. The airplane could be in a unrecoverable nose dive faster then could even realize what is happening.

Can the reversers be opened independently on left and right side? From some of the 3D plots on various threads it looks like the plane took a sharp left before diving. Could it be the left reverser malfunctioned or be accidently opened mid flight causing the plane to swirl left and lose the aerodynamic?

They can. Although incredibly rare. There are a few military airplanes that use reversers in flight to quickly drop altitude, but not used in any commercial passenger airplane that way. That scenario of only one opening, is also addressed in the video from Mentour Pilot that I linked. A few minutes earlier in the video. They have a checklist for it.

Do you work in the aerospace industry?

I think it was more than 6kfpm. The plane dropped from 22000 in 2 minutes. Especially the end was fast. The dash cam footage looks almost vertical.

Maybe the VSI was reporting incorrect data due to the crazy fast descent. Or it was a report from the beginning of the dive?

Oof man that's brutal straight down

Is it possible this was suicidal?

My morbid curiosity wonders if the passengers had internet.

Their phones might have but the passengers would be unconscious.

Based on what? As horrific as it might be it wouldn't surprise me if passengers were conscious all the way down. Even if oxygen masks didn't deploy or work, at 26,000 feet you have a few minutes of useful consciousness after rapid decompression [1]. Combined with the fact that the plane would be rapidly descending.

1: https://en.wikipedia.org/wiki/Time_of_useful_consciousness

G forces.

Nonsense. G forces are changes in speed or direction, those were pretty mild based on what we know right now, freefall or powered flight into terrain does not give huge G forces until impact.

I recall a similar nose down crash that saw 5G force before it was recovered at 11000 feet. But you seem to be very sure?

https://en.m.wikipedia.org/wiki/China_Airlines_Flight_006

5g forces on impact would imply the projectile stopped at ~50m/s^2 (numerically 5x the gravitational constant) deceleration. In a free fall, it hardly exceeds 1g, unless the aircraft was powering it to hurtle down faster

Read the accident report. It hit nearly 5gs on a powered descent and roll before the pilot recovered the plane.

Yes, it did. Now what does it tell you that the crew never lost consciousness?

G-forces are not experienced equally based on the axis on which the plane is moving or the speed at which it accelerates/decelerates. The airframe of that plane was deformed with the wings bent permanently indicating non-plastic deformation, and yet the passengers were fine.

Imagine a plane rotating on the axis through the COG nose moving 'down', that would give the pilots negative G, the people near the tail positive G and everybody in between something along a gradient, those near the COG would likely not experience much difference. If the plane came out of a steep dive then there would be a lot of positive G, and if someone were to black out that would likely be only for a moment. A powered descent into terrain would be far less in terms of G's than violent maneuvers such as steep banks or coming out of a steep dive.

Maybe I'm missing something: Why would the passengers be low on oxygen when they go into higher pressure air?

They wouldn't be. As the plane descends and the pressure increases the oxygen levels increase as well.

- JAL 350 - Germanwings 9525

You can't really rule that out a-priori any more and there are a couple where we likely will never know for sure.

anything is possible, it could also disintegrate midflight for whatever reason (bomb, factory/maintenance error), difficult to fly without wings for instance or with plane broken into two pieces

they found piece of wing away from crash site https://na.cx/i/xZu3nE9.jpg

2nd camera footage (dashcam) with total nosedive

https://twitter.com/Aviation_NewsTW/status/15058583238279987...

So, I think, the reason people are anxious about this particular crash is because the flight trajectory resembles the trajectories of 737-MAX crashes.

Although, this is not an MAX but 800 version of the 737, I think the first glance similarities are eere. However, there's no way the reasons are the same since that version of the plane doesn't have the MCAS system that caused the crashes.

My bet is on some horrible maintenance mistake making the vertical stabiliser inoperable or a human factor(terrorist attack or pilot suicide). I will be surprised if it turns out to be Boeing's fault as this model is extremely popular and has showed not tendency to nosedive(unlike the MAX).

no, it doesn't resemble MAX crashes which were under 45 degree descent, this was almost vertical 90 degrees judging by two unverified videos available

Here is the flight data: https://twitter.com/flightradar24/status/1505863117343014916...

The crash video only shows the last 1-2 seconds but in reality the plane seems to plunge spontaneously, then recover a bit and climb and finally plunge again.

It's not identical(this plane doesn't have MCAS) but it tells a similar story where the plane nosedives, recovers a bit and nosedives again - which is quite similar to the MCAS situations. I would say, the primary difference is that MCAS crashes happened during take off, on this one during a cruise.

>vertical stabiliser

I meant horizontal stabiliser

How about if it was to do with high angle of attack mode of speed trim system on 737 800? Don't think anyone trained on that, mind you they never was told about MCAS either... Either catastrophic failure which is highly unlikely, or something pushed nose down rapidly like on the Max, ie nose down trim. Actually come to think of it, look into the similarities with the Fly Dubai crash! They said the pilot held the trim forwards... yeah right!

So, as far as I can tell the model of 737 (the 737-800) is the predecessor of the 737 MAX. I believe this plane did not have the much maligned MCAS system. Nor the engines that affected handling so much that Boeing decided to add MCAS.

Edit: Wikipedia article on MCAS confirms. MCAS was introduced because the max is so different from the 737-800

Interesting. Will wait for report before further speculation but this was the first question that popped into my head.

Definitely not a MAX.

But it's still a Boeing. Which makes it a close enough fit to satisfy the needs of the people who's low effort commentary invariably drowns out any legitimate discourse about events like this.

>Wikipedia article

China Eastern Airlines Flight 5735 : https://en.wikipedia.org/wiki/China_Eastern_Airlines_Flight_...

The wikipedia article on MCAS: https://en.wikipedia.org/wiki/Maneuvering_Characteristics_Au...

"The Maneuvering Characteristics Augmentation System (MCAS) flight control law was implemented on the 737 MAX ... make the 737 MAX perform similarly to its immediate predecessor, the 737NG". Noting that the 737-800 is the long variant of the 737NG.

In other words, the MCAS wikipedia article states that MCAS was introduced on the 737-MAX so it would handle more like the 737-800. Which cements the conclusion that the 737-800 does not have MCAS.

MCAS was a bad sticking plaster on a different problem - that the 737-800 doesn't have.

To stick larger engines on the 737, they had to be moved forward. This meant that if the nose pitched up, there was a large area ahead of the wings "catching wind" and pitching the nose further. The MCAS was a "solution" to that - if it detected the nose pitching up, it would counter that by trimming down. In the MCAS-related crashes, the sensors malfunctioned and airplane just pitched down until it crashed.

it's NG version, MAX versions are still grounded in China

btw the plane was only 6 years old

An insightful prediction from Zhihu, which is Quora for China:

https://www.zhihu.com/question/517618431/answer/2356205623

This post is from 2022.02.20. It says that Chinese airlines have showed terrible security risks since COVID, because COVID creates great losses for airline industry. At the end of the post, it says that deadly accidenty is abound to happen.

Last air crash from Chinese airlines was 2010.

The crashed site is not far away from my hometown. RIP.

https://en.wikipedia.org/wiki/Correlation_does_not_imply_cau...

Zhihu is delete the links

Page is gone :(

Would love to have read it though, thanks for sharing.

As expected.

There is screenshot left.

https://i.redd.it/vlj0wyw9apo81.jpg

Wow that was fast. Can you speculate who is responsible for this? Internal compliance teams or were they served a “takedown notice” of some kind?

content deletion could be a result of internal compliance team, or direct command from government.

Translation based on screenshot: https://i.redd.it/vlj0wyw9apo81.jpg

The pandemic changed everything for the airline industry, which went into recession for two years. Pilots' incomes went down 10% to 40%, so did flight attendants' incomes, and losses were widen.

Last year, one of the "big three" airlines[1] recovered 100MMs RMB of revenue through selling pilots. Yep, selling pilots in stock, literally asking them to find jobs elsewhere. The airline industry is in a mess now, but the public doesn't know.

Young pilots complaining that they won't be able to make their mortgage payments; Low morale in the industry. Much higher attrition rates. What do they all mean for an industry that relies on safety?

1. A Qingdao Airlines aircraft ran over a ground crew staff [2]

2. Runway excursion for a China Eastern aircraft in ZLYL [3]

3. Landing gear pins were left not removed on a Lucky Air aircraft (subsidiary of Hainan Airlines) [4]

4. Cracked windshield on a Juneyao Air aircraft [5]

Those all happened within a year. Chinese civil aviation has never had a safety track record as bad as this. People in the industry feel very bad for such shameful moment.

But what would happen next? No idea. Everyone is waiting for that flight with the unlucky ones.

Translator notes:

* Original post was posted on Feb 20, 2022.

[1] Air China, China Southern, China Eastern

[2] Jan 24, 2022 https://www.sohu.com/a/519204416_123753

[3] Feb 11, 2022 https://news.sina.com.cn/o/2022-02-11/doc-ikyakumy5439933.sh...

[4] Feb 16, 2022 https://www.sohu.com/a/523129276_260616

[5] Feb 20, 2022 https://www.sohu.com/a/524074118_120388781

>Data from flight trackers indicate that the flight descended at over -30,000 feet per minute

Maybe someone well-versed could confirm but isn't that an absolutely insane sink rate even for a crash? I think the plane would have to be in a total dive right?

Scurity cam footage show that actually what happened, straight down 90 degrees

https://twitter.com/ChinaAvReview/status/1505834279275999236

2nd camera footage (dashcam) with total nosedive

https://twitter.com/Aviation_NewsTW/status/15058583238279987...

Thanks, total dive indeed, incredible.

The security cam footage makes me sick just looking at it. Poor people.

Airplane accidents are less frequent than car accidents or other modes of transportations but still it is so dramatic when one occurs.

Maybe it is because of the mass nature of it, in one stroke, a lot of people are killed compared to a car accident in which in each accident there are fewer parties involved.

Like how people fear nuclear power because of the accidents. Yet they do not fear coal, because it's so common place and looks unassuming.

I’m not sure what you mean by people not fearing coal.

No one wants a coal plant anywhere near them. That’s why pretty much all thermal power plants are located in poorer areas across the globe where the local communities do not have much political power.

You won’t find a single coal plant anywhere near where the richer people in a country live.

Also the (almost) binary nature. To me with car accidents you have at least the illusion of having some control over the situation. That a plane can just drop you out of the sky and you sit there doomed has always fueled my phobia of flying a lot.

Do you have a similar phobia when you are a passenger in an automobile? You have the same lack of control and a much higher risk profile...

Not quite the same lack of control. You can reach over and grab the wheel.

I think it may have to do with the fact that you're not directly responsible for the crash yourself. In a car, when you're driving it and have a crash, at least you had some control over it. At least that's how I feel about it, when sitting on a piece of metal flying through the sky, navigated by some person you've never met.

Similarly, if we ever have self-driving cars, people will probably be very harsh on those systems, even if they're 1000x safer.

Agree. It feels like "Roll you saving throw" every time you get on a plane. Self-driving car, the same.

I know it may not be logical.

People love to say it's about control, but I have no control when I'm a passenger in a car (and have no anxiety there). For me at least, I think it's more about: 1. A plane can't just "pull over". 2. The number of fatal car crashes out of the number of car crashes, vs the number of fatal aviation accidents out of the number of aviation accidents. I.e. in a car, my brain is reassured that accidents, when they happen, aren't as likely to be fatal.

This of course is illogical, as one ought to be concerned with simply the risk of death per mile, etc. But humans are far from perfect logic machines. I imagine kahneman and tversky have covered exactly this kind of bias at some point.

3. Fear of heights/falling.

If you're a car passenger and you see danger you can assist the driver in avoiding it. You likely know how to drive and are familiar with the procedures. In a plane you are completely disconnected from those in control, and unless you're a pilot or aviation buff you don't even really know what could go wrong.

That's true, although a car passenger does have the ability to see forwards, warn the driver of a problem, and request to be let out immediately if feeling uncomfortable.

Not a Max, for those asking.

https://www.aeroinside.com/16801/china-eastern-airlines-b738...

Changed title from 133 to 132, according to the report from state media.

It seems a passanger canceled his trip.

from what I read he was not let to board, because of issues with his health code app for COVID, if it's truth he can thank God for pandemic

Metacommentary: I’m seeing _a lot_ more attacks on the so-called average HN user, on the HN system, etc. here than I’ve noticed in any other thread recently. What’s up with that?

Sign of the times, unfortunately.

I hope you’re right, and that it’s not coordinated.

Interesting, yes, this is something I'm fairly convinced of.

I posted an Ask HN on this theme which - funny enough - got flagged:

https://news.ycombinator.com/item?id=30670690

Heh, go figure. And my original question here is downvoted enough here to be sufficiently invisible.

I don’t have sufficient karma to unflag your post, but I appreciate the pointer; it at least makes for good reading.

> -30,000 feet per minute

Isn't that 548km/h (340mph) and faster than terminal velocity? Nose would be pointed down.

Nose was pointed down according to some security cam footage (unverified).

https://twitter.com/ChinaAvReview/status/1505834279275999236

>terminal velocity?

https://en.wikipedia.org/wiki/Terminal_velocity

If you read the ^^ wikipedia page, you will see the NASA 'Terminal Velocity' url complete with Calculator;

https://www.grc.nasa.gov/WWW/K-12/airplane/termv.html

Terminal velocity depends on the object. The terminal velocity of a skydiver is around 200km/h. I'd imagine the terminal velocity of an airliner pointed straight down would be significantly higher even without the engines running. With engines at cruising power they move 700km/h+ in horizontal flight, I'd imagine they could exceed that by a lot in a vertical dive.

NASA has this online Terminal Velocity calculator. For drag coeficient typical values for commercial large planes are in the order of 0.05.

"Terminal Velocity Calculator":

https://www.grc.nasa.gov/www/k-12/airplane/termv.html

Best rough figure I could find for weight of a loaded 737 is around 40 tons, frontal area I'm guesstimating is roughly a 3m diameter cylinder plus ~0.5m average thickness of the 28m wingspan giving 21m^2? For which the calculator gives 262.8m/s or 943.2km/h.

Not far from current preliminary estimates.

"China Plane Was Travelling At Speed Of Sound As It Slammed Into Hill":

https://www.ndtv.com/world-news/china-jets-fatal-dive-took-i...

"The Boeing Co. 737-800 was knifing through the air at more than 640 miles (966 kilometers) per hour, and at times may have exceeded 700 mph, according to data from Flightradar24, a website that tracks planes.

"The preliminary data indicate it was near the speed of sound," said John Hansman, a Massachusetts Institute of Technology astronautics and aeronautics professor who reviewed Bloomberg's calculation of the jet's speed. "It was coming down steep.""

Horrible. I feel so bad for the families of all the victims.

Ok, did anyone find out what happened here?

Seriously, is there any data on Chinese air crashes or is that unknown?

I know I'll get downvoted again but here's my resolution for life: will never fly on a Boeing airplane again.

Edit: I know the statistics, I just get horrible fears in planes and Boeing is all over the news, hence me avoiding them. To each its own, I guess.

I'll downvote you for a poor grasp of statistics. Today a few thousand flights on Boeing equipment took off and landed safely around the world. One crash, without any news whether it's Boeing's fault, and you make up rules for the rest of your life.

To draw an equivalence, do you still breathe air with an airborne virus running amok?

We need a system where you could only downvote you, if you could post proof of a recent flight on a Boeing. Easier to avoid if you are in Europe.

Is it? I fly in Europe often enough (usually the cheapest flight I can find) and I almost always end up on a 737. Ryanair for example has 249 737-800s out of a 258 planes fleet.

https://simpleflying.com/ryanair-fleet-2021/

For the MAX

"How To Avoid Flying The Dreaded Boeing 737-MAX" https://www.godsavethepoints.com/how-to-avoid-flying-the-dre...

To look for Airbus

"These Airlines Are Airbus' Biggest Customers" https://simpleflying.com/airbus-biggest-customers/

What's the point in making a generalization based on such a narrow experience? If you're often choosing Ryanair or Norwegian, of course you'll often fly on a Boeing aircraft.

EasyJet and Wizz are 100% Airbus.

You are right, my bad. I thought I've also flown with Boeing with those but only double checked Ryanair.

Might as well not fly any plane then, considering that Airbus' fatal accident rate is almost the exact same as Boeing's.

>For Airbus, Boeing and Bombardier, the differences are almost negligible. So they can be considered equally safe. [0]

And that is even after the 737 MAX incidents.

[0] https://turbli.com/blog/the-safest-planes-to-fly-in-by-accid...

I'm not sure the article captures the danger of forward risk well given the argument that Boeing and cost management practices have hijacked the approval process and design strategy, respectively, and the current inventory includes planes recent models with poor track records.

In the next few years I think we will see if process failure has been a momentary blip or if this article is viewed as having fallen into the same trap as judging 1960 aviation on averages of entire period of flight instead of on rate of improvement.

Put a different way, I wont be estimating the safety of the 787 on the safety of a 737-MAX because most of the systems of the MAX were designed in an earlier Boeing/FAA system that bears little resemblance to the modern Boeing process, yet I am still comfortable flying in a 737-MAX.

So you'll avoid some of the safest planes, and at least 50% of all air travel routes on the planet. Sounds like a plan.

"Plane Crash Rates by Model" -> ( Rate of fatal passenger events per million flights.) -> Data up to 2017

http://www.airsafe.com/events/models/rate_mod.htm

You can pick and choose. As different airlines have different track records for maintenance quality that is also likely to be as important, or more important.

Just two examples:

Boeing 737 (all models) -> Rate -> 0.24

Airbus A318/A319/A320/A321 -> Rate -> 0.09

Does China generally release information on aviation crashes? I've wondered how many accidents, crashes, and incursions they've really had.

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