ORIGINAL: EddieWeeks
I think Anhedral is rarely used to change stability. There are far more effective and efficient ways to decrease stability than
Bending the whole wing down. Most of the time a full size plane will have anhedral
Because for other reasons. Most common use is with wing tip landing gear. A high wing plane line the
Harrier or B52 would not be very unpractical with very long wing mounted gear. Also I think, with high wing planes, anhedral is
Used to get into ground effect sooner. The C17, witch is primary a heavy lifter, would benefit greatly by keeping its wings
Close to the ground as it can . There Is no point in changing the stability of a C17. There is no question anhedral does change
Stability a small amount, but in most cases anhedral is built into planes for other reasons. FWIW I can’t think of any US fighter that
Have anhedral, except the F104 star fighter.
Eddie Weeks
Oh gees.
"A side effect of dihedral can be roll-coupling, a tendency for an aircraft to "corkscrew" through the air under certain conditions. This rolling motion, called a dutch roll, is unpleasant to experience, and can lead to loss of control or can overstress an aircraft. A certain amount of anhedral can combat this effect. Pronounced anhedral is also often seen on aircraft with a high mounted wing, such as the BAe 146, Lockheed Galaxy and others. In such designs, the high mounted wing itself confers roll stability (due to the pendulum effect of the fuselage, engines, etc), so additional dihedral is not required. In fact, such designs can be excessively stable, so the anhedral is added to cancel out some of the roll stability to ensure that the aircraft can be easily manoeuvred.
Sweptback wing also increases roll stability. This is another reason for anhedral configuration on military aircraft with high sweep angle, as well as on some airliners, even on low-wing aircraft such as Tu-134 and Tu-154."
From:
http://en.wikipedia.org/wiki/Anhedral