> Alex Perry writes: > > I suspect the LaRCSim is the most accurate. It is possible to taxi > > (carefully) with those winds, but takes considerable planning and > > operation of the controls to make it work out safely.
David comments: > The tests were run with the plane stationary, engine at idle, and no > brakes applied. In those circumstances, wouldn't a weathervane be most > likely? I'm not sure; I've never been in sustained winds that strong. A weathervane is a weakening effect as rotation starts; enough wind to cause rotation will also cause the aircraft to tilt over on the landing gear. Terrain shape in the vicinity of the aircraft will modify the wind flow; if there is a tiny upward component near the upwind wing, you're in trouble. Either the aircraft rolling slightly, or the wing flowing upward slightly, is enough to expose a positive angle of attack of the main wing to the wind. The wing aspect ratio inverts, so it becomes an extremely effective lifting body on the upwind side; the downwind side is baffled by the airframe and the detached boundary layer on the upper side of the wing and so has very little lift. This converts the wind-based lift into a roll torque that increases _quadratically_ with the angle of rotation (i.e. no pilot warning). For a slight headwind, or a slight tailwind, you can use the ailerons to modify the effective angle of attack and oppose that rolling torque. However, the stated example is exactly at 90 degrees and thus this would have no effect. In real life, you'd zigzag down taxiways and very carefully change the control positions as you go (watching windsocks like an eagle). _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
