Developing Flight Test Techniques to Ensure Proper Rigging of Highly AugmentedAircraft

摘要

Uncommanded rolling moments have been considered a natural part of the agingprocess of some F/A-18 airplanes. These rolling moments can range from an annoyance requiring constant trimming to a serious degradation in handling qualities which can cause premature departures during maneuvering flight. Uncommanded rolling moments in flight can generally be eliminated with rigging if the surface which is causing the roll is known. Due to the highly augmented flight control architecture of the F/A-18, it is very difficult to isolate the actual control surface that is causing the uncommanded rolling moment since so many surfaces are active. NAWC-AD has developed techniques to identify the flight control surface causing uncommanded rolling moments. These techniques have been used successfully on four F/A-18 airplanes to identify which flight control surface was causing uncommanded roll rates. Additional flight tests are planned to further refine the techniques described in this paper. These techniques have been demonstrated to reduce uncommanded rolling moments in the F/A-18 and can be applied to all aircraft.