Research on Method of Fixed Load Aerodynamic Center in the Flight Test for Civil Aircraft

AC 25-7c requires the fly-by-wire aircraft to use the HQRM method to evaluate its flight quality under the degraded mode control law. In the flight test stage, the longitudinal static stability needs to be evaluated to get the position of the fixed load aerodynamic center, so as to determine the afterward limit of center of gravity. In this paper, the flight test contents and methods are designed according to the principle of aerodynamic center. Then the data analysis, risk analysis, error analysis and the control of weight and center of gravity carried out.