Digital simulation of flight control systems for post-stall aircraft

Digital simulations of aircraft with normal-acceleration, pitch-rate, and angle-of-track command flight control systems capable of PST (poststall) flight were successfully developed. Analysis of test cases showed the shortcomings as well as the strength of each configuration. The aircraft configured with the pitch-rate command flight control system exhibited the greatest pitch-roll and pitch-yaw coupling problems and was oversensitive in pitch. It is suggested that adjusting the gain slightly, adding pitch-roll and pitch-yaw crossfeeds and modifying the existing aileron-to-rudder and roll-rate-to-rudder interconnects should minimize this problem. The angle-of-attack command aircraft reacted sluggishly to pitch inputs. It is suggested that adding lead-lag compensation will lower the vehicle´s rise time