justageek

What do you do if all engines fail between V1 and V2? You won't be getting any more acceleration so you're not going to make it to V2, right?

f9999

If all engines fail there's one way to get more speed, which is to lose altitude. Besides flapping really hard that is. So if you're on the ground staying there is probably a good idea.

* disclaimer - I don't know how to fly a plane, but am moderately adept at paper airplane technology

Blumie

Someone can correct me if I'm wrong, but I imagine the odds of two engines failing on a modern jet is statistically zero (i.e., the odds are measurable, but are so small as to be meaningless).

PDX-PLT

So if they don't, how do they get a new engine there?

I think on the 747's, there's a spare engine mount. What about the 777's?

YVR Cockroach

Truck it, or use a big heavy-lift (more big than heavy) transport to fly it in. The big Antonov transports that are seen in SEA frequently are flying in 777 engines.

I think only the 747s had these. The 777 engines would probably be too big to fit (close to the diameter of a 707/727/737/757/A320 fuselage).

marlborobell

If you look at the track, you can see pretty much exactly where they made a hard right turn, and it's a little north of Montreal. That strongly suggests that Montreal was a much closer airport than JFK when the decision was made to divert. And I think we can all agree it's a suitable airport to land a 777. We can also agree that even with one engine out, the captain has the right to go to a more distant airport providing that he can justify his decision.

That said, the pprune posting suggested that one engine was already out and its structural integrity was in question when they decided to divert -- if that was not the case, I apologize. If an engine is just failing to do its job (but not posing a physical hazard to the plane) then going an extra 300 miles is most probably justified -- if there's a legitimate worry that it's going to fall off its pylon or suffer an uncontained breach then (IMHO) it generally isn't.

jcf27

This case is very unlikely to happen. You do not specify when the double engine failure between V1 and V2 occurs. Different emergency procedures apply based on altitude, weather, and other criteria.

Between V1 and V2, you have Vr (which is the rotation speed. It must be equal or greater than V1). V1 is the minimum speed in the takeoff roll, following a failure of the critical engine at Vef (speed at which the critical engine is assumed to fail). Once V1 is reached, the pilot still can take off with an engine out. Attaining V2(takeoff safety speed) will be done done at a slower pace. The pilot will attempt to maintain Vyse (best rate of climb with a critical engine inop.) Proper inflight emergency procedures are to be executed.

All multi-engine pilots are trained to take off with the most critical engine inoperative.

Enjoy your flights....

Cheers,

J

f9999

The odds of them failing mechanically are extraordinarily low. There is one achilles heel, which is what happens if fuel is exhausted (which would basically never happen on takeoff, but still).

I remember when this happened, it's one of those great stories if you're an aviation fan:

http://www.google.com/search?hl=en&c...glider&spell=1

Blumie

Unreal. Here are all the details:

http://www.answers.com/topic/gimli-glider

jcf27

Contaminated fuel is another cause of engine flameout on T/O. It has happened many time in piston engines. Overconfident pilots do not check for contamination in the fuel (mostly water). The engine may run for a few minutes, and then.... kaput, when you least expected it !

Cheers,

J

oklAAhoma

Yes, the plane was physically closer to YUL than to JFK when the diversion occurred. But that didn't necessarily make it the most suitable airport. In post #12 of this thread AEpilot76 stated that"


Apparently suitability means much more than simple proximity. Undoubtedly, the pilots made their decision after studying all of the pertinent details and weighing several options. That seems far preferable to choosing a course of action based only on a look at the flight path. YMMV.

us2

Put me down as one who thinks the pilots made the right call here. Diverting to YUL would entail customs issues and the probable result that a number of passengers would be stranded. The divert decision was made prior to the engine failure and it sounds like the actual failure occurred as the aircraft was nearing JFK, which then would be the nearest suitable airport. Moreover, since AC does not operate the 777, you'd have a plane on the ground waiting for an engine, a situation much less likely to occur at JFK where AA has maintenance facilities and possibly a spare aircraft. In fact, Flightaware showed 134 continuing on to London not that long after its arrival at JFK (about 5 hours).

http://flightaware.com/live/flight/A...449Z/KJFK/EGLL

YVR Cockroach

Hmm, after looking at flightaware.com, I went to look for my SO's flight - a much-delayed UA flight from ORD. I changed the airline but before I could get the right flight number, it gave me status of today's UA134 which is a 777. It was on a SFO-ORD run and had to divert to SLC because of engine problems.

kappa

Deleted=Wrong Thread Oops!

altaskier

I was on a Delta 757 a month ago, SFO 10 pm to JFK 6 am. I take that flight a certain amount and use iPod/Eytmotic ER-4P earphones and eyeshades (plus a glass of wine in CRC beforehand) and always sleep through the flight - yet I always seem to wake up when I feel the aircraft descending about 20 minutes prior to landing. Well, this time I woke up, rubbed my eyes, and looked out the window to find myself puzzled: sure didn't look like NY area! Turns out we did an emergency landing in Detroit. I slept through the loss of engine and pilot announcement, but still woke up for the big change in speed and attitude of descent. The point is that the loss of an engine in midflight is at least less dramatic a change in flight profile than descent...