KLMBLue
Posts: 264
Joined: Fri Nov 17, 2000 5:36 am

Can A 747 Or 340 Do This?

Mon Feb 05, 2001 9:11 am

Can a B744 or a A340 do the following?
1. Say the the two outer engines(the two farthest apart) fail. Can the two inner engines keep the airplane flying, and for how long?
2. Or the two inner engines fail, can the two outer engines keep the airplane in the air?
I know it sounds redundant asking the two different questions, but I am just wondering! Thanks in advance.
KLM
 
AirbusDriver
Posts: 228
Joined: Mon Feb 05, 2001 8:01 am

RE: Can A 747 Or 340 Do This?

Mon Feb 05, 2001 9:23 am

yes both can fly with any 2 engine out at max gross weight.
 
baec777
Posts: 1232
Joined: Sat Oct 30, 1999 5:01 am

RE: Can A 747 Or 340 Do This?

Mon Feb 05, 2001 9:24 am

The B747, A340 can fly with 2 engines for not so long, but they can fly for 1-2 hours during a declared emergency landing procedures until they land the plane(s).

Baec777  Big thumbs up
 
prebennorholm
Posts: 6562
Joined: Tue Mar 21, 2000 6:25 am

RE: Can A 747 Or 340 Do This?

Mon Feb 05, 2001 10:15 am

They will easily keep flying at low altitude on two engines only.
They will be in somewhat worse condition than a twin which beyond V1 speed actually must TAKE OFF with half of the power lost - with flaps and gear down etc.
Otherwise they wouldn't be able to climb to and cruise at high altitude where the max power is roughly one fourth due to the thin air.
Both planes have a lift to drag ratio around 20 and a power to max weight ratio around 4 at sea level. So even with only one engine operational - if it was placed on the centerline - and consequently power to weight ratio of 16, they would still be able to climb slightly. But that would depend very much on the condition of the disabled engines - what drag they would produce.
But with a light load - a lot of fuel either burned or dumped - they would both easily maintain flight on one inner engine only at low altitude.
Best regards, Preben Norholm
Always keep your number of landings equal to your number of take-offs

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos