Airliners.net Civil Aviation: A345 And B772LR

Airliners.net Civil Aviation: A345 And B772LR: "The wing structure of a four engined aircraft has to be stronger, not to fly but to support the engines on when the aircraft is on the ground. Having engines farther out on the wing is a benefit in terms of bending relief while the aircraft is flying, but when there is no lift the wing has to support the extra bending moment of those engines plus fuel, plus its own structural weight...

As far as operations of 777-200LR and A340-500 are concerned the 777-200LR for any given payload and range burns less fuel, period dot. The 777-200LR basic aircraft structure is 55,000lbs lighter than the A340-500 so it requires less thrust to move through the air and it's GE90 engines are more efficient in terms of SFC than are the Trent 500's. Inside the 777 has more floor area and more flexible cabin space than does the A340 allowing wider seats and greater number of possible cabin class layouts..."