737 MAX pilots scoured manual in minutes before Lion Air crash in Indonesia
38 replies, posted
The pilots of a Boeing 737 MAX frantically scoured a manual before
their plane crashed into the Java Sea in October, killing all 189 people on board.
Recordings from the cockpit of the Lion Air plane suggest that the pilots were struggling to understand why the jet was lurching downwards, but ran out of time before it hit the water.
Two minutes into the flight, the first officer reported a "flight control problem" to air traffic control and said that they intended to maintain an altitude of 5,000ft.
That's fucking terrifying
Just imagine every possible sense telling you it's smooth sailing from here and then the computer takes over and freaks out on you, diving you straight into the earth while you try to figure out how to override it for what seems like the longest 9 minutes of your life.
Why again does the plane not have a master override switch for manual control?
Think there would be some simple and extremely obvious override that didn't even require looking through a manual in the first place.
It's honestly quite scary.
It does, but it's not labeled and pilots aren't even aware that this system exists, let alone where the switch is to turn it off.
This is exactly why I dont trust driverless cars.
This seems like classic criminal negligence to me. The system is reliant on one singular & apparently error-prone sensor and the software evidently doesn't perform any basic sanity checks before deciding the failed sensor's readout is correct and forcing the plane into a fatal dive.
The sensor isn't getting physically stuck, the fact that it thinks the nose is vertical (and therefore tries to force it down) says to me the AoA sensor in its failure state is just reading at its upper limit like a bad hall sensor, probably showing solid 90 degrees. Basic software sanity checks should cover this type of failure:
A sudden jump from normal, slightly varied AoA to solid 90 degrees is obviously incorrect and therefore should result in the system shutting down.
The AoA sensor reading solid 90 degrees (or some other crazy value) while other sensors aboard the plane are showing normal readings means the sensor has obviously failed, which should result in the system shutting down.
An AoA sensor showing any solid reading is almost certainly broken or stuck and therefore the software should not be making any course corrections based on it.
This type of software check is literally no different from checking a player's coordinates in a video game and finding them well outside of the hardcoded map boundaries. If some value is obviously incorrect, you reset.
Beyond that, at the hardware level, no system capable of lawn darting the aircraft should be reliant on just a single sensor's output.
This isn't a rational attitude to have, though. It's also not a fair comparison.
Pilots are trained for thousands of hours to do their jobs on top of the experience they accumulate throughout their entire career.
On the other hand almost anyone can get a driver's license and human drivers are notoriously unreliable (if not dangerous) compared to automated cars.
Airplane autopilot, much like lane assist systems in cars (or even Tesla's own "autopilot") are not meant to replace pilots, but simply act as an assist so that pilots can focus on other tasks rather than the tedious task of keeping a plane straight and level at a given altitude or flight level for hours on end, and maybe save their asses if something goes wrong (TCAS). It's meant primarily to reduce workload. In aviation we use the term "automation complacency" for when an incident happens because the pilots were too over-reliant on the autopilot and reduced their situational awareness to dangerous levels.
This has already manifested to some capacity in Telsa, there's been a couple of occasions where fatal crashes have happened because drivers became over-reliant on the assist and were not ready to take control back when it was needed. In a way "driverless cars" as someone like Google envisions them, aren't truly the future of automobiles, especially not cars with no steering wheel whatsoever, it's a detached silicon valley utopia vision (as is typical of silicon valley); the future of cars owned by the average person is something more like what (commercial) airplanes are today. Capable of doing most things by themselves but a human hand is occasionally needed and even encouraged as to not lose situational awareness and cause a crash, so in essence it's a heavily assisted machine. It's easy to forget that the road world has a lot more variables than the air, and I say this as an airplane pilot. It all works very well when all the sensors are working, the road is paved, all the lines on the road are properly painted and all the traffic lights are working but the software and hardware is only as perfect as the humans who build them and we see this in aviation every day.
I can't say too much about commercial aircraft though because every plane I've flown so far was built in the 80's, has a carburetor engine and no assist whatsoever beyond elevator trim and the most complex piece of electronics in it is the transponder.
The weird thing is that the plane has two of those sensors, but it simply picks the result from the sensor associated with the flight computer that is currently used - which is determined by who's flying the plane. So basically, if the captain's in control, one sensor is used, if the 1st pilot is flying, the other input in used. Which seems kinda insane when you'd at least be able to check that the sensors don't agree, and notify the pilots of that fault (or at least automatically shut off MCAS, since the input has 50% risk of being junk).
Not an aerospace engineer, either, and this is also just what I remember from a NYTimes article, so grain of salt - still though.
And this is why I laugh at people who say automated trucks will take over for drivers.
Look at this. A multi-million dollar company who has access to top of the line everything still managed to completely and utterly fuck up. This cost hundreds of people their lives. The same will happen to automated trucks, and has already happened to automated cars.
I have no doubt that automatic trucks would be able to completely take over specific tasks, like deliveries from a warehouse to a distribution center where packages will then be spread across smaller vehicles, where a truck has to do not much more than drive to A from B within white lines on motorways, but certain types of trucking that require a bit more than that (especially logging industry related shit where trucks have to slowly navigate narrow dirt roads with no markings while also dodging holes on the road) being completely automated just sounds like wishful thinking unless you have an actual super-intelligent AI capable of decision making. Trucking in rural areas, perilous places and shitty Russian roads where lanes are guesswork is a lot different than trucking around LA and San Fran.
But I'd say it's a safe bet that truck driving as a job is going to take a sizeable dent.
It is labelled and it is a core emergency procedure that every 737 pilot is required to know. There are two trim cutout switches on the center pedestal. It's called "runaway trim" and the procedure is immediately to flip those switches and manually take control of the trim using the trim wheel on either side of the throttle quadrant, which would be spinning around before the cutout switches were flipped, giving the pilots an indication that the trim was being adjusted without their input on the yoke. That's why they are there, as a visual indication of what the trim is doing, and has a fold-out handle and trim angle indicator for purely manual mechanical input. Are the AOA sensors and software faulty? Hell yeah. However, it is on the pilots to know this emergency procedure, and the lion air pilots clearly didn't know proper emergency procedures.
welp, there goes Boeing's place as a world leader in aviation. Good thing brexit is going to gutpunch airbus so bad they won't be able to compete
Airbus is French though?
It's really sad that they wouldn't have found anything as the system is entirely missing from the manual... I hope the idiots that were in charge of that decision go to jail.
The day before the crash the pilot had pulled out the plane from dive. Next day it happened again and the Lion Air 737 MAX crashed
airbus has a wing plant in britain
I had read elsewhere that the MAX has no clear indication that the system has been engaged or how to regain control of the aircraft. I'll defer to you.
Imagine spending the last 9 minutes of your life reading a manual to find your issue.
Maybe not a caution popping up on the screen, or a tone, but the trim wheels will spin, letting you know that the trim is being adjusted by the computer.
Trucks and planes are pretty different dude.
This is an example of corporate criminal negiligence and greed.
The technology works, in principle but fails to because of broken sensors and other various issues.
It's so much more than being a "automation" issue, that it's a bit dishonest of you to use this as justification for your own career.
This is a corporate greed issue more than anything.
It's more of a European endeavor. They've got plants in several countries (mainly France and Germany).
It's actually quite complicated -- and a more complicated version of this problem is solved in Google's Paxos, which is considered extremely goddamn confusing -- to handle multiple sensors and determining if an error is occurring and which sensor(s) to trust.
That said, for goddamn Boeing/aviation, it being complicated is absolutely no excuse. They've implemented these systems before.
EVERYTHING ELSE is redundant on aircrafts. Every system has at least one fallback. Yet, a system that plunges the goddamn plane into the ground doesn't?!
well well, thats fucked
Well, I hope Boeing get (justly) gutted for this one.
"optional safety features" what the fuck
Yeah I couldn't believe it when the guy in the twitter thread said this. How the hell is this legal.
On one side, it was the airlines choice to buy the planes and NOT buying safety features, not defending boeing not making it standard in the first place, its ridiculous, its also ridiculous lion air did not purchase upgrades when they had way more than enough money to do so. Not surprising considering they have a poor safety record.
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