Handling Qualities Evaluation Of The XV-15 Tilt Rotor Aircraft

Handling quality evaluations of the XV-15 Tilt Rotor Aircraft have used model testing, digital flight simulation, piloted moving-base simulation, and a variable stability helicopter. Powered and unpowered wind tunnel model testing has delineated aircraft aerodynamics and rotor-airframe interference effects for use in a mathematical model. Digital computer programs are being used to obtain trim and stability characteristics. Pilot opinions and engineering studies are being made on the moving-base simulators at NASA-Ames to evaluate the control system and cockpit layout. Proper simulation of visual cues and control system dynamics were found to be very important for correct interpretation of the aircraft characteristics. The Canadian NRC in-flight simulator in a Bell Model 205A-1 helicopter was used to compare the collective stick with an airplane throttle lever for controlling the height of the tilt rotor aircraft in helicopter mode. This paper describes the various methods used in the evaluation, and presents some of the results obtained to date and planned evaluations for later in the program.