Flight Control System Development on the B-1 Program

The B-1 is a long-range strategic bomber designed to perform safely in a hostile environment with a high probability of mission success. The flight control system achieves these objectives with redundant hybrid combinations of fly-by-wire and conventional design techniques. The primary mode of control in each axis is fail-operational, fail-safe, fly-by-wire with simultaneously operating mechanical control. The flight control system is described, and selected flight and ground test experiences and resultant development activity are discussed. Developments include reduction of force fight in surfaces with multiple actuators, reduction of horizontal stabilizer control hysteresis, elimination of pitch control/structural mode coupling, reduction in lower rudder load oscillations, increase in the operational reliability of the flap/slat system, elimination of the susceptibility of the augmentation system to electrical power transients, and other items.