Spectral Theory of Buffeting and Gust Response: Unification and Extension

The statistical approach to the dynamic response of aircraft in turbulent air is generalized and extended. The basic element is the response of the airplane to flight through an inclined sinusoidal upwash pattern in (a) three, (b) two, or (c)—without inclination-—one dimension. Case (a) is general; in case (b) the airplane is idealized as a lifting surface or a lifting line; in case (c), as a lifting point. Earlier results of Liepmann are recovered in the cases of a lifting line and a lifting point. An extension of the case of a lifting line is made for the sweptback lifting line, and an extension of the case of a lifting point to provide rolling moments due to spanwise upwash gradients. The general case (a) and the lifting surface in case (b) are new.