Quantitative feedback theory (QFT) was applied successfully to enhance the
robust stability and tracking performance of the pitch flight control syste
m for a remote pilotless vehicle (RPV), within its full flight envelope. Th
e influence of control surface loss or damage to the dynamic derivatives of
the aircraft model can be treated as an extension of the model uncertainty
robustness problem. QFT is applied to the analysis and design of the fault
tolerant flight control system allowing for possible control surface damag
es.