Development and Evaluation of an Inverse Solution Technique for Studying Helicopter Maneuverability and Agility

Abstract : An inverse solution technique for determining the maximum maneuvering performance of a helicopter using smooth, pilotlike control inputs is presented. Also described is a piloted simulation experiment performed on the NASA Ames Advanced Cab and Visual System to investigate the accuracy of the solution resulting from this technique. The maneuverability and agility capability of the helicopter math model was varied by varying the pitch and roll damping, the maximum pitch and roll rate, and the maximum load-factor capability. Three maneuvers were investigated: a 180-degree turn, a longitudinal pop-up, and a lateral jink. The inverse solution technique yielded accurate predictions of pilot-in-the-loop maneuvering performance for two of the three maneuvers. For the purposes of this study, maneuverability is defined as the maximum achievable time rate of change of the velocity vector at any point in the flight envelope, and agility is defined as the maximum achievable time-rate-of-change of the acceleration vector at any point in the flight envelope.