Longitudinal stability of a wing-in-ground effect aircraft

This thesis is a study of the longitudinal stability of a Wing-In-Ground Effect (WIG) aircraft. The WIG aircraft is designed to fly at altitudes up to one-half the wing span of the aircraft. These low altitudes allow the aircraft to take advantage of the ground effect phenomenon for performance benefits.; In this study, the governing equations of the WIG aircraft are derived through modification of the traditional Euler equations using a small disturbance theory and are then solved for the stability roots of the aircraft. The stability derivatives used are actual data from a C-130 military transport aircraft.; The results reveal that as WIG stability derivatives are introduced, the aircraft will exhibit both short period and phugoid oscillatory motions. These motions are shown, under certain conditions, to cause the ride quality to become uncomfortable and suggest the need for artificial damping of the aircraft longitudinal motions.