2 engine failure

[brs planespotter]

after reading the thread on the a380,i was wondering if any of the 4 engined a/c,a340 b744 suffered a double engine failure on the same wing would this be catastrophic?it may sound outrageous but i thought u never know!cheers too all

[763 jock]

R & N?

[kingoftheslipstream]

it may or may not be, depending on the weight of the aircraft and it's location with respect to terrain when the failures occur.

Statistically it's highly unlikely.

We practise it once 'n a while in the simulator. We have procedure to follow to keep it safe 'n effective.

[brs planespotter]

simon chowder

apologies,i thought i was,must be gremlins in the computer!

[BOAC]

brs - what 763 is (kindly) trying to say is that you should select fine pitch and **** *** to Spotters! I guess you'll be 'ducked' shortly.

[simonchowder]

More like a gremlin on the computer brs.

[Exaviator]

"double engine failure on the same wing would this be catastrophic?"

On 747 this would require a two engine drift down during cruise followed by a two engine approach and landing. During the approach no gear until landing is assured and then no go-around available. What a lovely aircraft

[411A]

SVA had a two engine out (on one side) on a 747SP years ago, departing JED bound for JFK...max weight, second engine 'failed' (actually, shut down in error by the idiot Flight Engineer, without saying anything to anyone) at about 1000agl, flaps/LED's retracted on speed schedule, and the aircraft began to climb at 'round about 200agl over the beach....very close, that one.
And...yes I knew the Captain...and the idiot Flight Engineer...and said F/E was lucky to remain out of jail....just.
Exit only visa for him, poste haste...(should have been shot on sight for his bone-head original actions).
You are unlikely to find this listed anywhere, all hushed up at the time.
707?
Yes, it will fly on two as well, WAT depending.
L1011, fly on one?
Yup, sure will, provided 210 knots can be achieved, clean, with reasonable ambient temperatures and mid-weights.
Skill required?
Yup, but not unreasonable.
RTFB and follow the plot promptly, for best results.

There...that should answer the original question.

[simonchowder]

Thats almost as scary as the bone headed captain who shut the wrong engine down in the Kegworth fiasco

[Rainboe]

On a heavy 747 Classic going off from Nairobi or Johannesburg, a double failure at rotate would provably not be survivable. The flight engineers often used to have the fuel jettison panel open ready to start spraying out immediately at 2000kgs/minute. The 747-400 would make it, being more powered, but it would be very hard work and has to be skillfully flown.

In cruise, we lost an engine at high altitude and had to come down to 25,000' in a Classic 747. Still made Chicago. A second engine loss would be down to about 15,000' and much more serious, but no problem.

[Intruder]

The extra power on the -400 would make it likely less survivable in the "failure at rotation" scenario, since its Vmc would be higher...

I've had 2 symmetrical engines failed at V1 in the sim (max TOGW), and the airplane just barely got off the ground. With the added drag of full rudder, I think the asymmetrical case would be questionable at best.

[Rainboe]

Boeing certificated the -400 with better rudder response than the Classic. Can you imagine a company like Boeing pumping up the engines and systems of the 747 and not bothering with making any improvements to asymmetric handling? In all respects, the -400 handling was vastly improved. Two engine out approaches went from being a crisis to a relative breeze on the -400. On the Classic, you were committed to hitting the ground, on the -400 the whole thing was far more civilised.

[parabellum]

The GA, with gear extended, on the B744, two out on the same side, is possible, takes a lot of gentle handling and I have only ever practised it in the SIM from about a minimum of 500AGL, (main wheels usually touch the runway), up to 1000AGL which is a better teaching exercise as, at medium weights, it can be done, right through to clean, just!

[Intruder]

Boeing certificated the -400 with better rudder response than the Classic. Can you imagine a company like Boeing pumping up the engines and systems of the 747 and not bothering with making any improvements to asymmetric handling? In all respects, the -400 handling was vastly improved. Two engine out approaches went from being a crisis to a relative breeze on the -400. On the Classic, you were committed to hitting the ground, on the -400 the whole thing was far more civilised.

I'm qualified in both, current in the Classic, and last flew the -400 in June.

The rudder "response" is virtually identical in both. The rudder authority, relative to engine thrust, is virtually identical. That is, both are just short of the limit at a V1 cut -- both can overcome a bit of yaw and drift rate, but not much. Vmcg at max thrust, 15C, sea level is 133 in the -400, 129 in the Classic -- not much difference, but with the Classic still having a bit more margin.

Manual handling of the Classic is, IMO, better overall than the -400. The exception is throttle response, which is much better in the -400. However, the -400 does have significantly more ground effect apparent, which will aid a 2-engine-out situation IF you can get in the air under control.