FREQUENCY-EFFECTS ON DYNAMIC STABILITY DERIVATIVES OBTAINED FROM SMALL-AMPLITUDE OSCILLATORY TESTING

As a result of a continuing program of work to establish a basic under standing of the aerodynamic phenomena that influence agility, stabilit y, and control of future combat aircraft configurations, it has become clear that the conventional stability or aerodynamic derivative model for the representation of aerodynamic loads in the aircraft equations of motion is no longer adequate. This paper discusses the limitations of the stability derivative model for modern combat aircraft maneuver s, in particular the problem of motion frequency effects in static and dynamic derivatives derived from small-amplitude oscillatory wind-tun nel tests, and presents an alternative modeling technique based on the concept of an aerodynamic transfer function.