An improved helicopter flight dynamic model suited to evaluate the flying qualities of a single rotor helicopter was built for UH-60A, including trim calculation and stability and controllability derivatives. On this foundation, the open-loop flying qualities of the UH-60A helicopter were studied by using MIL-F-83300. According to the requirement, the change of the UH-60A dynamic response and the control characteristics were computed and compared when some typical aerodynamic configuration parameters were adjusted, the influences of the aerodynamic configuration parameters on flying qualities and the sensitivities of flying qualities with respect to the parameters were analyzed.