MDHC's Enhanced Diagnostic System, A Unique And Comprehensive Approach To Structural Monitoring

Currently in the helicopter industry, structural component lives and inspection criteria are established by damage tolerance or safe life methods. An accurate determination of the loading spectrum of the component is required for both methodologies. Structural monitoring of aircraft through the use of flight data recorder technology could substantially reduce the uncertainties in the load spectrum used in component life analysis. McDonnell Douglas Helicopter Company has developed a multi-functional flight data recorder system for the Army's AH-64A Apache Helicopter. One of the primary functions of the Enhanced Diagnostic System (EDS) is to obtain operational loads data. EDS structural monitoring is unique because it uses aircraft mission subsystems data as well as strain gage data to monitor loads and aircraft usage. The purpose of this paper is to describe the EDS structural monitoring approach and to propose a methodology for using the EDS structural loads data in a comprehensive Structural Integrity Program.