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Boeing 787 Suffers Rare Dual Engine Failure on Landing

thepointsguy.com

101–110 of 365 posts

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#101

Did anyone else find it odd that it took 40 minutes to get the plane towed back to the terminal?

It probably takes 15 minutes to drive there, 10 minutes to hook up the plane and 15 minutes to drag it back. Seems to make sense to me.

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#102

Boeing’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…

This is an issue carmakers have had to deal with, too, since the invention of the automatic transmission: what if you put it in reverse while driving on the highway?

There are a number of YouTube videos with people who have tried it. The answer, in a modern car: pretty much nothing. It just stays in Drive. On one car, it turned on the backup camera display!

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#103
post #40

How do you restart the Boeing 787 in mid-air? With the lack of an APU (they use li-on batteries, I think?), what's the mid-air engine restart procedure?

The 787 absolutely has an apu, I think you may be confusing engines with no bleed air.

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#104
Seems like reasonable choice on the Boeing's part, the objective of the reverse thrust is to provide additional braking to the aircraft, if shutting down the engine has similar effect (albeit to a lesser extent), why not? Better than getting stuck in a dangerous situation if the reverse thrust was deployed prematurely.

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#105

Earlier quoted context omitted.

and causing trouble for everyone You mean killed 189 people, right? https://en.wikipedia.org/wiki/Lion_Air_Flight_610

To save people the reading, the safety feature triggered was an automatic dive maneuver initiated by the flight computer as a result of an incorrect angle-of-attack sensor reading causing the plane to believe it was in a stall, when it actually wasn't I didn't look into it any further, but based on that alone I would agree that this seems like a shitty feature, perhaps a loud alarm or other warning would be more appr…

The 737 is a short and stubby airliner with its center of thrust far below the rest of the aircraft. The 737MAX version added upgraded, powerful engines. It is theoretically possible for the engines to flip the aircraft up and out of control if power is applied too quickly in certain fight situations.

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#106

Earlier quoted context omitted.

and causing trouble for everyone You mean killed 189 people, right? https://en.wikipedia.org/wiki/Lion_Air_Flight_610

To save people the reading, the safety feature triggered was an automatic dive maneuver initiated by the flight computer as a result of an incorrect angle-of-attack sensor reading causing the plane to believe it was in a stall, when it actually wasn't I didn't look into it any further, but based on that alone I would agree that this seems like a shitty feature, perhaps a loud alarm or other warning would be more appr…

A big issue with that flash was that there was a way to disable the feature, but Boeing didn't tell anyone about it and it wasn't documented anywhere.

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#107

Did anyone else find it odd that it took 40 minutes to get the plane towed back to the terminal?

It might make me worry about their fire response capability. On the other hand, there's probably an element of triage involved here (no immediate threat once the runway was closed). More generally, I would expect problems that a tow truck solves to not be as urgent as problems that a fire truck solves, so garaging the tow truck farther away seems plausible.

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#109

Earlier quoted context omitted.

There is a notion of blame wrapped up with "too quickly".

I'm having a hard time thinking up an alternative choice of words that is similarly clear and concise. I also think that the phrase "too X" is polysemous. Depending on how it's used, it may imply a notion of blame. But it can also just be a way of describing an incompatibility. "This clearance is too low for that truck" and "This truck is too tall for that clearance" are entirely equivalent statements, IMO. Neither i…

>I'm having a hard time thinking up an alternative choice of words that is similarly clear and concise.

There's "beyond a certain speed", but still something of a mouthful.

Re: Boeing 787 Suffers Rare Dual Engine Failure on Landing

#110

Boeing’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…

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 would be to just"...

Ah well, glad a 5 sentence comment on the internet can resolve an issue in a hardware, software, and social engineering challenge decades in the making.

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