Excuse me? Did someone just mention that the A340 is better than the B777 for hot-and-high? Uh- no. A340-200/-300 are actually underpowered....
Dear N-156F, The terms "underpowered" and "overpowered" are irrelevant. What is relevant is "runway performance". How long a runway is needed with a given payload and fueled for a given range.
Any twin drops to 50% power with an engine out while a quad drops to 75%. Therefore, if they were equally powered, then the twin would need a much longer runway. But the airports don't have specially long runways for twins only
so the plane manufacturers put in more power instead.
Read the runway requirement specs on the company web sites instead.
That said, the 340 also requires quite some runway. But then the design criteria didn't include to be operated from 6000 feet regional airport runways. It was designed to houl a considerable payload over a very long distance between large airports, and do it in an economic way. And that's exactly what it does.
Then there is the "visual fooling": When you see a 340 take off, then it is because the airline needs that 340 range performance, or you would see the cheaper medium range 330 instead. When you see a 777, then you can never know. Often they take off for a US domestic coast to coast flight with less than half full fuel tanks, and that of course transforms a powerful twin into a rocket. You never see a 340 on such a short sector, they always take off with full or almost full fuel load, and the fuel is almost half of the total weight.
Even on Atlantic routes neither the 340 nor 777 can't stretch their legs - the preferred Airbus is the 330 and they mix with 747s, 767s and plenty of 777s.
Best regards, Preben Norholm