MH-47G DAFCS Directional-Axis Control Law Development

This paper presents the new directional-axis control laws for the MH-47G Digital Automatic Flight Control System (DAFCS). The MH-47G DAFCS reduces directional-axis pilot workload, reduces system weight and complexity, and is currently being fielded. The new control laws successfully replace sideslip differential pressure feedback with lateral acceleration feedback. Trim-prediction technology is used to provide automatic directional trim management. Important design considerations are discussed, including the selection of a turn-coordination reference point, externally-slung load damping, and the use of the ADS-33E-PRF Slalom MTE for control law development. Simulation and flight data are included to illustrate the new control laws' superiority over the old control laws. The paper is suited for experts in handling qualities and flight control design, as well as engineers in other disciplines with working knowledge of flight dynamics.