Is ground effect used only in short-field take-offs, or sometimes soft-field too?
Ground effect is a phenomenon that is observed no matter whether landing or taking-off. Furthermore, it is observed in any condition including short field, soft field or normal operations. To answer your question a little better, in my experiences ground effect is most used in soft field operations. The purpose of a soft field take off is to keep as little weight off of the landing gear as possible. In order to keep the nose wheel from getting stuck in the turf, a pilot must keep the yoke pulled back on the take off roll to perform almost a “pop-wheelie” down the runway. Then because of the heavy back pressure on the yoke and elevator input, the airplane will begin to climb prior to reaching Vx (Best Climb Angle Vertical Distance) or Vy (Best Climb Angle for Time). The reason you are air born prior to reaching Vx or Vy is because you are in ground effect which is the buffet of air pressue between your wings and the ground. If you were to continue to climb before reaching either Vx or V
