Matt D
Topic Author
Posts: 8907
Joined: Fri Nov 19, 1999 6:00 am

Stretching Things A Bit

Wed Dec 20, 2000 1:09 pm

Although there are a number of "stretched" planes out there, I want to focus on 2 models in particular: The 737-900 and the 767-400.
Those planes represent the longest stretches of any plane from the original design. Both are so long as to look almost comical.
So what are the limits that which an airliner design can be stretched? Taking into account the center of gravity, how long can a plane be made before it would be at risk of collapsing from under its own weight?
Also what about rotation considerations at takeoff? The 739 in particular looks to me like it cannot achieve a very high AOA at rotation because the exceedingly long fuselage and the fact that it has original 737 landing gear-which means it sits like a Mexican low-rider to the ground-would put the plane at risk of scraping the underside at very high speed.
Would taller landing gear alleviate these problems?
Is this a genuine concern or am I overlooking something?
Posts: 817
Joined: Tue Aug 08, 2000 10:34 am

RE: Stretching Things A Bit

Thu Dec 21, 2000 5:20 am

Landing gears are tricky. When a plane is lengthened the mains often are lengthened too. The rotation needs enough clearance. But the nose gear isn't always lengthened. This is expensive when the nose gear retracts close to the nose cone. If there is room the nose gear might get lengthened.

If the mains are at the point of needing to be moved outboard in order to fit when retracted this can get expensive too. Therefore sometimes a stretch becomes a new aircraft.