Influences of aerodynamic configuration parameters on helicopter flying qualities

The UH-60A helicopter nonlinear flight dynamic model suited to evaluate the flying qualities was built. Trim calculation of the model was conducted, stability and controllability derivatives were calculated, and the agreement between the computational results and the referenced data indicated that the model is feasible and effective. The open-loop flying qualities of the UH-60A helicopter were studied by using flying qualities specification of military helicopter (GJB902-90). According to the requirements, the change of the UH-60A dynamic response characteristics and the control characteristics were computed and compared when the selected aerodynamic configuration parameters were adjusted, the flying qualities sensitivities with respect to the parameters were analyzed. The results show that, changing the rotor height has a significant impact on each quality, the decrement of tail rotor height can improve roll attitude change level, and the tail rotor longitudinal position is a major factor affecting yaw attitude change and yaw attitude response.