It's likely software as they suspect. Another possibility is that there was something wrong with the fuel.
The young 777 had a vaguely similar situation that was caused by a fuel filter freezing up
Boeing 787 Suffers Rare Dual Engine Failure on Landing
141–150 of 365 posts
Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#142The Boeing 787 is now about nine years old. I wonder how much of this is operator proficiency triggering latent bugs (aka, "pilots got too good at pushing buttons quickly"). The bugs in the Therac 25 were only discovered after the machine had been in production for a while (you had to be typing "too quickly" in order to get the software to trigger the bug with the safety interlock).
It's not very typical for pilots to push buttons quickly. Especially not the thrustreversers and engine and flight controls.
But it is entirely possible that nobody pulled the reversers while still airborne in 9 years, because it's a very strange thing to do. A bit like opening your car door while still driving 60 mph... Nobody does that in normal operation.
Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#143The Boeing 787 is now about nine years old. I wonder how much of this is operator proficiency triggering latent bugs (aka, "pilots got too good at pushing buttons quickly"). The bugs in the Therac 25 were only discovered after the machine had been in production for a while (you had to be typing "too quickly" in order to get the software to trigger the bug with the safety interlock).
Make me think about could we use a robot to fuzz physical inputs.
Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#144The Boeing 787 is now about nine years old. I wonder how much of this is operator proficiency triggering latent bugs (aka, "pilots got too good at pushing buttons quickly"). The bugs in the Therac 25 were only discovered after the machine had been in production for a while (you had to be typing "too quickly" in order to get the software to trigger the bug with the safety interlock).
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Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#145I would bet this is going to get a lot more common as a whole generation of heads-down nerdy programmers who got into the industry because of sheer geek joy get replaced by Stack Overflow copy/paste Uber brogrammers who are just looking for a paycheck to fund their weekends in Tahoe. I mean, that's OK and all, but they need to stick to making Fyre apps that crush it by changing the world through social influencers or…
Oddly enough, your comment makes me think that you are writing it from the perspective of a member of the very group of programmers you decry. Companies that write high-risk, life-critical systems don't just let any ole J. Random Hacker work on such critical systems, and I don't think anyone who has worked in such a field would realistically think that these "brogrammers" as you say would be seriously considered for such a position. Companies don't play around with this kind of thing as failures are EXTREMELY expensive in terms of both funds and reputation.
Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#146Earlier quoted context omitted.
Do you have experience with aircraft engine design, or landing protocols, or insight in to the meetings when the engines were designed? If so, I'll take back my words but considering the manufacturer doesn't know exactly why this happened, and the engineers on the ground said it seems like a "software bug", it seems a bit presumptuous and frankly a bit comical to start saying things like: "Surely a better solution wo…
Reminds me of the quote, "For every complex problem there is an answer that is clear, simple, and wrong." -- H.L. Mencken One of the things I have experienced in my career is the mind boggling complexity of the software in systems that are capable of killing people. The more people it can kill the more complex the software. As a result when I read articles like the one posted I find it tantalizing to speculate about…
Relevant article: "Reality has a surprising amount of detail"
http://johnsalvatier.org/blog/2017/reality-has-a-surprising-...
Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#147The Boeing 787 is now about nine years old. I wonder how much of this is operator proficiency triggering latent bugs (aka, "pilots got too good at pushing buttons quickly"). The bugs in the Therac 25 were only discovered after the machine had been in production for a while (you had to be typing "too quickly" in order to get the software to trigger the bug with the safety interlock).
Considering the level of fly-by-wire that goes into airframes nowadays, I could certainly see such features added to older airframes through flight-software updates after they are already in service. I have no idea if that's how it's done in the field, though.
Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#148Boeing’s answer seems to say if you accidentally pull the thrust reverser lever before the aircraft is on the ground it just force shuts down the engines. That sounds like an odd safety override. Surely a better solution would be to just not activate reverse thrust. Unlike car engines a jet engine can’t just be quickly restarted if it accidentally shuts down. It typically takes 30-60 seconds to get going. This and ea…
Thrust reversers can never be deployed while airborne. This engine shutdown system is only enable on the ground. It's designed to shutdown an engine if the engine thrust doesn't match the commanded thrust, so an engine malfunction on the ground cannot cause the plane to taxi out of control.
But it is still possible for the pilots to deploy reverse thrust too soon, after touchdown but before there there is enough weight on the wheels to provide sufficient steering. I'm guessing the pilots deployed too soon, and discovered a new corner case.
Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#149I would bet this is going to get a lot more common as a whole generation of heads-down nerdy programmers who got into the industry because of sheer geek joy get replaced by Stack Overflow copy/paste Uber brogrammers who are just looking for a paycheck to fund their weekends in Tahoe. I mean, that's OK and all, but they need to stick to making Fyre apps that crush it by changing the world through social influencers or…
Oddly enough, your comment makes me think that you are writing it from the perspective of a member of the very group of programmers you decry. Companies that write high-risk, life-critical systems don't just let any ole J. Random Hacker work on such critical systems, and I don't think anyone who has worked in such a field would realistically think that these "brogrammers" as you say would be seriously considered for…
Aren't almost all of the software engineers on those projects writing tests and formally verifying software?
Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing
#150Earlier quoted context omitted.
and causing trouble for everyone You mean killed 189 people, right? https://en.wikipedia.org/wiki/Lion_Air_Flight_610
That aircraft was being knowingly flown with [edit: a broken sensor]. It was unsafe on takeoff. The final problem that brought the aircraft down - the trim run-away - happens all the time in airliners you've flown in. When the run-away starts, the pilot is supposed to flip two switches to disable the trim system motors. In the Lion Air crash, it is indeed believed that a software bug from the misbehaving sensors star…
> the trim run-away - happens all the time in airliners you've flown in.
It doesn't. A trim run-away is a very very serious incident for any pilot.
There are procedures to deal with it, and we check trim override in pre-flight checks, but it's absolutely not an everyday thing.
> 737's are even safer here than many airliners, because after you disable the electric trim motors, you have manual wheels in the cockpit that you can rotate to set the trim back to what it should be. Some other airliners in common use don't have these manual trim controls - you have to disable a trim run-away in time, or it's game over.
This is not true at all either. There are no planes with a single electric trim that you cannot override. The FAA and EASA would refuse to certify those.