What the Lion Air Pilots May Have Needed to Do to Avoid a Crash | Hacker News Reader

What the Lion Air Pilots May Have Needed to Do to Avoid a Crash

nytimes.com

118 pointsuger48 comments

Great article, unfortunate choice of title and opening image.

A lot of people are going to skip reading it, and assume this is an article blaming the pilots for this accident, rather than pointing out that neither the airline nor pilots were informed about Boeing's new systems and so couldn't have been trained to counteract it.

Boeing's new system wasn't even in the updated manual. And therefore it wasn't in their QRH, which is likely what they were using while attempting to resolve the issue.

> With only fragmentary data available, Mr. Hansman said he suspects that a runaway of the M.C.A.S. system played a central role in the crash. “The system basically overrode the pilot in that situation,” Mr. Hansman said.

Every thread so far about this topic however have managed to find a way to blame Lion Air, or simply point out how much they suck while glossing over the actual facts.

Replacing/overriding humans by shoddy AI will become bigger and bigger problem. From the Gmail auto-suggestions to the labyrinth of voice recognition options when you call your credit card or an airline this is all a part of an unfortunate trend.

Honestly if the aircraft just communicated what automated actions it was taking better, it may not have been so fatal.

"STALL AVOID - STABILIZER ADJUSTED - STALL AVOID - STABILIZER ADJUSTED" would be kinda hard to ignore. Even if they forgot to put it in the manual.

Then on most modern aircrafts, these alarms would be going off all the time. It's more important to know why the computer received incorrect data on the angle of the plane.

Usually there are three or more sensors reading it and the master computer uses the voting mechanism to arrive at the correct reading. So in this case probably the master computer had erred?

I don't understand. Do most modern aircraft fly right at the edge of their ability to stay in the air?

Not in climb, cruise, or descent. Only on maximum performance takeoffs and the last moments before touchdown are modern airliners near the edge of the envelope of controlled flight.

Engine "Stalling" is not a big issue at all. As a part of training we purposefully stall engines and recover from it. And as angle of attack increases due to increase/decrease in wind speed, engine stalls can be more frequent that usual.

You are conflating two separate things. Stalls in the aerodynamic sense (angle-of-attack above critical) have nothing to do with the engine "stalling" (engine-out) which is a mechanical failure.

I should have used better terminology. The article here describes aircraft stalls and I was talking about the same.

Aircraft stalls are not extra-ordinary events and with auto pilot on the computer is always adjusting the angle, speed , preventing stall etc.

Can we please stop calling this AI!? This is well within the established control theory. Nothing about flight controls is "AI".

While we're at it, can we stop using AI buzzword? Nothing about current state of machine learning is AI.

Then how will we have unicorns or find employment for marketing mbas?

Voice recognition used to be AI, then we developed it.

A roomba used to be AI, then we built one.

Neural nets used to be AI, then we figured out how to make them practical.

Is a self-driving car AI? Probably not, since we have prototypes now.

Nothing about our current state of anything will ever be AI because AI just means "computers doing things computers can't do". As soon as we understand how to make a computer do something, it's no longer AI.

I think it's more "things we assume thought process is needed to manage". Because we use thought processes when we do them.

This is also where the disconnect is coming from. We have self-driving cars now, so (an alarmingly good chunk of) people assume the car has thought processes. While in reality the car is more like blind walking than having the experience you and I have while driving a car. Certainly it's not thinking any thoughts.

"Any sufficiently advanced technology is indistinguishable from AI."

I'm sure people thought computers were "AI" when they first did a complicated multiplication problem.

I don't think there is a qualitative difference between what's going on in a human brain and a self driving car.

Please someone correct me if I'm wrong; but that is not what "we" mean with A.I. Neural net is actually one. It is the ability "to learn themselves through self-feedback". I don't think we have it covered down, as in we don't fully understand the outcome. It gives great results, like pretty generated pictures. And we do know the process, but the outcome is still unpredictable.

>"to learn themselves through self-feedback"

But now you're describing machine learning, which many people would describe as "applied statistics, not AI".

>And we do know the process, but the outcome is still unpredictable.

Unpredictable because you don't understand the statistics or unpredictable because of the size of the computation being done? Neither of those indicate "AI". Or maybe unpredictable because a relatively simple algorithm unexpectedly gives rise to good results? Then we're back to the roomba that just randomly moves until it bumps into something being AI.

There's no good definition for AI. It's like superfood. You can argue that it means high in antioxidants or high in fiber or probiotic, but at the end of the day, it's the marketing departments that determine the definition.

The article blames the new system in the very first paragraph, before it mentions anything else. And in the third paragraph it explains how Boeing mishandled its installation. Only then does the article mention pilots - and when they are mentioned, they are excused, rather than blamed.

So the evidence does not support your worries.

Shutting off power to the stab trim system is not complex, and it's why the switches are right there on the console. The wheel and the sound it makes are right there and make it obvious when the stab trim system is running.

And ten minutes should certainly be enough to do that. For that matter, if you're constantly pulling back the yoke to stay level... Wouldn't you try setting the trim manually?

Yea, runaway trim is a failure pilots are aware of. That big wheel spins whenever the trim changes so they would notice the huge wheel turning, unprompted, while pulling back on the yoke. This doesn't seem like the whole story though. They clearly were able to control it for a while and were probably making trim inputs so why the sudden descent? They probably didn't turn off the trim motors as the article suggests but should have been able to keep re-trimming the aircraft indefinitely.

There's definitely more to the story, as the information we have just doesn't add up.

Investigation of the wreckage should clearly show what position the stab trim was at. It's a large nut on a jackscrew, the disintegration of the airplane should leave that intact. The nut/jackscrew is built out of incredibly strong steel.

Maybe this?

Pilots have long been taught that pulling back on a 737's control column can arrest that condition – a fix pilots call a "breakaway", says the APA.

Indeed, American's runaway stabiliser checklist, dated 10 July, says, "stabiliser trim commands are interrupted when the control column is displaced in the opposite direction".

But the APA has now learned that the 737 Max is apparently different.

https://www.flightglobal.com/news/articles/airline-industry-...

Some aircraft have yoke aft limit switches that disable electrical stab trim I believe.

As has been stated above, stab trim runaway is common knowledge and an emergency procedure (EP) that is trained for. Arresting the descent with yoke while activating the electrical stabilizer trim cutout and having the pilot-not-flying manually rotate the stabilizer wheel in the opposite direction or at least attempting to hold it from adding more trim if cutout is not working.

Many pilots will position a knee or shin on the stabilizer wheel so they are aware when trim is being run. The yoke itself holds a trim adjustment mechanism so the pilots can adjust trim while retaining arrest authority on the yoke as well, though in the case of runaway trim the cutout would be used and manual operation of the wheel would be required.

I believe another commentator mentioned the jack screw, this will very likely have survived the crash and investigators will be able to tell exactly where the nut was positioned (trim setting) when impact occurred.

With stab trim runaway being such well trained for EP [assumed as its common in my circles] I would be surprised if that were the root cause unless pilot error is attributed to suspecting another fault mode.

I am not familiar with commercial aviation as much, is it common place to transition from the critical phase of flight during take off to autopilot (AP) climb at such a low altitude? If they were not on some sort of AP mode I can't see how they wouldn't notice the trim being added as a serious issue.

-Sorry I had meant to post this as a response above and not directly to your post

Most APs are certified for use from 400' above-ground-level on departure and on a complex departure procedure or in weather, that's not an uncommon engagement level.

There's a fair number of people who think that pilots are relying on "George/Otto" too much and should do more hand flying, but I'd imagine if you peered into 100 airliners on departure, that 95 or more of them are on autopilot somewhere below 5000' AGL.

I guess it's a drawback of the news cycle, but it seems kindof premature to start doing detailed 3D renderings of the 737 cockpit when basically nothing is known except one update to the plane manual. If we just wait a few month, the investigation report will no doubt clarify exactly what the pilots needed to do.

Words like "certainly" are generally unhelpful in these situations. It may seem "certain" to you sitting in front of a computer. It may be less certain sitting at the controls of a misbehaving airplane, at low altitude, during a busy phase of flight.

Air crash investigators collect evidence and don't bother speculating because of the multiple possible scenarios: eg, open mind getting it right with patience vs. closed mind getting it wrong now with speculation because they have to feed their own, "superior" ego to "declare" the "cause"... as right as often as a know-nothing know-it all.

It's not in this NYT article, but from this one (https://www.cnn.com/2018/11/15/business/boeing-lion-air-cras...) apparently Boeing's stock has slid 8% likely because investors worry that it will have a huge liability associated with this.

Doubt it. As a non-USA incident on a non-USA airline, compensation will probably end up being a new plane for the airline and a thousand dollars per passenger for funeral expenses.

Blows my mind that Boeing decided not to include this new system in the “updated” manual.

To be fair, this procedure is not "new". There is a condition known as "stabilizer runaway" that can occur when there is a failure in the automatic systems that control the stabilizer trim (for the autopilot, etc). This procedure is exactly what you would do in that situation to address this issue.

The problem is the MCAS addition to MAX adds a new failure mode that the pilots weren't expecting, and it occurred during a very busy phase of flight.

You can’t advertise no new training if you update the training material.

These articles make it sound like settled fact that this crash was caused by the anti-stall system. Is that really the expert concensus?

"Investigators and experts are uncertain why Lion Air Flight 610 plummeted...But they are focusing on an automatic system designed to keep..."

That's the opener. Seems reasonable to me.

Slightly off-topic:

This is an ATC recording where pilots lost control over the aircraft. Figuring out what to do when the aircraft goes to random directions, they ask for the direction of the ocean to ditch in. Because of low visibility they have no idea where they are going.

The description suggests that during maintenance, some steering control was attached in the wrong way.

https://youtu.be/kIc8Rr-cKd8

In this case, the pilots have like an hour to figure out how to control the aircraft.

If they actually reached the sea they would ditch it sooner. Because of the faulty controls they couldn't orient themselves, and more important, the airplane did not turn the way they wanted it to, and kept jumping altitudes. Because of that, at some point they kinda started to figure out how to manhandle the jet, while waiting the Portuguese F16s to come and help orient them. If I read correctly somewhere, the autopilot had enough life in it to keep the plane basically flying. If they were closer to water, maybe this would not be such a happy story.

The fighter pilot(s) and ATC did a whole lot actually, they seemed willing not to give up and let them just ditch. The fighter pilots obviously new the local conditions and airports very well and led them to land.

Sadly, the Lion Air had a different malfunction, they did not have time to react. Maybe, just maybe, another crew would, but that's not the point. It is pointless to sorrow about people not doing something they were not trained for, and possibly not even aware, in a profession heavily dependent on training and procedures.

Reminds me of the Air France Flight 447 crash, where a unexpected manual mode leads to confusion and cognitive overload with no time to recover.

> and cognitive overload with no time to recover.

I don't think the Lion Air Pilots would've been able to recover at all, even if they didn't experience a cognitive overload.

> These steps were not in the manual, and the pilots had not been trained in them.

Source: OP

These steps are most certainly in the manual. Here's the QRH page from a [different dash number] 737. "No new training" strongly suggests that this QRH procedure is in the 737-Max as well.

NNC 9.1 (non-normal checklist "Runaway Stablizer") here: http://jira.icesoft.org/secure/attachment/21680/qrh%20rev36%...

Am I missing the interactive part of this article? Seems like a bunch of static images. Would be cool if it let you perform the operations in some way.

Oh the humanity! The NYT has established themselves such a great reputation of publishing high quality interactive data driven articles, that now people expect them to include a fully functional flight simulator that lets you relive the doomed pilot's last few minutes, like the Kobayashi Maru!

That sure would be cool, but some readers might find it a bit too shocking.

To be fair, the URL does have "interactive" in it so expecting some form of interactivity would not be unusual.

You have to open up the JavaScript debugger console to see the interactive job ad, where you can interactively evaluate JavaScript expressions like: document.location = 'https://developers.nytimes.com/careers';

           0000000                         000        0000000

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         000         11       0     1111111100              000

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    NYTimes.com: All the code that's fit to printf()

    We're hiring: developers.nytimes.com/careers

To their credit, they've come up with an unobtrusive way around AdBlocker that selectively targets web developers.

  https://www.nytimes.com/interactive/2018/11/16/world/asia/lion-air-crash-cockpit.html

>interactive

Last week I saw the Pilot putting the plane in Autopilot instead of handing over to copilot/trainee pilot when he went to loo.

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