The U.S. Army's Aviation Engineering Directorate led the first phase of a program to develop modern control laws (MCLAWS) for the AH-64D Apache Longbow to provide improved handling qualities for hover/low speed flight in a degraded visual environment. The design approach uses the existing partial authority stability augmentation system to provide both attitude command attitude hold and translational rate command response types over a useful range of aircraft velocitites and attitudes to reduce pilot workload in degraded visual environments based on the requirements in ADS-33E. These new response types are integrated into a full envelope set of control laws providing a viable upgrade to the existing aircraft. Control law gains were optimized relative to handling qualities and control system performance requirements based on a high fidelity, analytical model drawing on deep system knowledge of relevant hardware and software related dynamics. A piloted simulation evaluation showed reduced pilot workload and improved handling qualities for the MCLAWS over the legacy flight control system.

This paper is located in the AHS International 63rd Annual Forum (TL716 .A1 A512 2007 VOL.2).