C-17 flight control system overview

The authors discuss the basic requirements which drove the C-17 design. They explain the background behind the deep stall avoidance, probability of loss of control, all-engine-out control, and safe go-around requirements. The overall flight control system (FCS) design is presented. The FCS features which satisfy the above requirements are described. The C-17 combines the best features of a modern fly-by-wire system with the best elements of a traditional mechanical system. This combination results in a system which is flexible enough to optimize the capabilities of the C-17 yet redundant and dissimilar enough to provide protection against a wide range of failure conditions. Specific failure modes and their design safeguards and the early flight test results are reviewed. During the first six months of flight test the aircraft accomplished almost all its major objectives ahead of schedule. Several minor anomalies were encountered during the early flight test program. These anomalies and their effect on the final flight control design are discussed