in aviation, the angle between the longitudinal axis of an airplane and the airplane’s flight path relative to the earth. The drift angle is the result of a crosswind. It usually coincides with the angle between the flight path relative to the air medium and the flight path relative to the earth, since the slip angle is ignored (the slip angle is the angle between the airplane’s longitudinal axis and its flight path relative to the air medium). During a landing approach, a pilot compensates for the effect of a crosswind by slipping or by changing the heading by an amount equal to the drift angle.