ONBOARD AUTOMATIC AID AND ADVISORY FOR PILOTS OF CONTROL-IMPAIRED AIRCRAFT

Existing approaches for recovering aircraft after control failures are unsatisfactory. This work reflects consideration of the aircraft control failure problem from a broader viewpoint. Postfailure performance and operating constraints best taken explicitly into account are discussed, and the role of explicit postfailure retrim is presented. Automatic onboard emergency control is seen to be a very significant part of the problem of recovering from a control failure. A rule-based expert system approach was taken to find successful control strategies after jam elevator failures on a C-130 aircraft. The system is described and demonstrated. As a general means of augmenting traditional control reconfiguration, this type of approach seems to be a way of directing use of any remaining control capability, or use of the unusual or counterintuitive ideas sometimes required in recovery. Aspects of a postfailure pilot advisory function, proposed for use in more quiescent periods of flight after first failure accommodation, and also amenable to the expert system approach, are described briefly.