In Lion Air Crash, Black Box Data Reveals Pilots’ Struggle to Regain Control
nytimes.com
nytimes.com
There's still more to learn about this disaster played out. But if what we've learned so far holds up -- that Boeing added a significant feature without proper communication or obvious way to override it -- I hope Lion Air 610 becomes part of the ethics curriculum in engineering classes, along with Therac-25 and the Hyatt Regency walkway collapse [0].
[0] https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse
Dealing with this is relatively simple:
1) Hold the trim wheel. Autopilots are designed so that humans can easily override just by holding the control.
2) Disable the autopilot / M.C.A.S. via switch.
3) Pull the circuit breaker. Even if they pull the wrong breaker(s), flying with a partial panel is safer than flying without controls.
The version of the article that I read says:
"The pilot of Flight 610 appears to have [pressed that switch] repeatedly to bring the nose up, but the MCAS reactivated each time, as it was designed to do, forcing the nose back down, and the pilot had to repeat the process again and again."
This is getting quite wierd. The captain had 6000 hours of experience, the pilots knew what the problem was, they had ten minutes to solve it, and they had started to do the right things. All good so far. Then, something went wrong. But what?
I wonder if the system showed a warning that was active to give the pilots a hint of why the aircraft behaved the way it did. Even if they didn't know about MCAS, a warning that it is active would've at least triggered further responses (e.g. cut off power to the systems to return to manual control).
Couple of interesting excerpts:
Lion Air’s flight manual did not contain information about the new anti-stall system, according to investigators and an airplane flight manual seen by Reuters. U.S. pilots were also not made aware in training courses, pilot unions say.
Pilots can stop the automated response by pressing two buttons if the system behaves unexpectedly, the FAA says.
Pilots on a flight from Jakarta to Bali the day before the crash experienced a similar sensor issue but managed to land safely by turning off the system, the New York Times reported.
This sounds like a communication failure rather than an explicit technical failure as the system was overridable. Lion Air wasn't exactly well known for not being dodgy here so there was a possibility in the 10 minute flight window they couldn't resolve the issue.
The prior flight called in a panpan distress signal for the exact same sensor failure and subsequently disabled the system to continue flying.
No one is really meant to communicate this to a commercial pilot, they're expected to read it themselves pre-flight.
> If the Boeing emergency manual dictates that there are cut off switches to disable the system and return to manual control, it would be a training issue with the flight crew. Boeing obviously added this flight characteristic to the planes for a specific reason and also documented how and what it could do after their own test flights. Wondering how many airlines are not going through the entire aircraft's training publication to understand this system.
Which is a little odd as the article itself said that Boeing's new M.C.A.S. system was not in the manual and or training documentation. Boeing's very carefully worded statement is a deflection, they're essentially arguing that even though they added a new undocumented system, that existing protocols for other problems (runaway stabilizer trim) could be used to resolve this one.
How do the NY Times pick the "Times Pick" comment? Is reading the article you're commenting on not a prerequisite?
I understand that it probably SHOULD have been read, but I'd imagine that a line about this particular scenario could easily be overlooked even if one did review the emergency procedures for the MAX aircraft before piloting it. That is still a pretty flimsy excuse even if there is a grain of truth. This isn't some Monday detail that will cause a redeploy next week. A large number of people are dead as a result of this accident.
How a system that can so stubbornly keep overriding manual input made it onto a modern aircraft is concerning. I will admit that I am not in the industry and am speaking from a platform of ignorance, but it's less than comforting knowing that I may go up in a plane with such technology in place.
Hell, every aircraft is slightly different and the pilots and/or service people don't treat them as such (although in practice typically the differences may be negligible for the pilots -- but they will check).
So based on that it is absolutely the airline's responsibility to make sure that the people operating any equipment are checked out on it.
So it is possible (though pretty unlikely) that Boeing failed to follow their protocol, e.g. didn't send out the right notices on a timely bases or something, and if so they would be responsible. But with all the airframes they've shipped over the decades that's pretty unlikely.
From what I have been reading in other articles (sources available if you wish), most of the comments from folks in the industry have been that Boeing DIDN'T give the normal, proper notice to airlines. The prevailing sentiment is that most everyone was caught relatively unaware that this feature had been shipped on the new airframe. Mind you this is mostly hearsay from mainstream media, so I am taking this with a grain of salt. Oversights tend to get sensationalized.