Accession Number : ADA309236

Title :   Feasibility Study of a Rotorcraft Health and Usage Monitoring System (HUMS): Usage and Structural Life Monitoring Evaluation. Phase 2.

Descriptive Note : Final contractor rept.,

Corporate Author : BELL HELICOPTER TEXTRON INC FORT WORTH TX

Personal Author(s) : Dickson, B. ; Cronkhite, J. ; Bielefeld, S. ; Killian, L. ; Hayden, R.

PDF Url : ADA309236

Report Date : FEB 1996

Pagination or Media Count : 68

Abstract : The objective of this study was to evaluate two techniques, Flight Condition Recognition (FCR) and Flight Load Synthesis (FLS), for usage monitoring and assess the potential benefits of extending the retirement intervals of life-limited components, thus reducing the operator's maintenance and replacement costs. Both techniques involve indirect determination of loads using measured flight parameters and subsequent fatigue analysis to calculate the life expended on the life-limited components. To assess the potential benefit of usage monitoring, the two usage techniques were compared to current methods of component retirement. In addition, comparisons were made with direct load measurements to assess the accuracy of the two techniques. The data that was used for the evaluation of the usage monitoring techniques was collected under an independent HUMS Flight trial program, using a commercially available HUMS and data recording system. The usage data collect from the HUMS trial aircraft was analyzed off-line using PC-based software that included the FCR and FLS techniques. In the future, if the technique prove feasible, usage monitoring would be incorporated into the onboard HUMS. The benefit of usage monitoring was identified under work accomplished during the first phase of this activity. The results from the operator's perspective is presented in the report NASA CR198446 (ARL-CR-289; DOT/FAA/AR-95/50). For the selected dynamic components analyzed, the results of the evaluation of the FCR and FLS techniques indicate a potential for extending retirement lives. This is due to the damage accumulation rate for the FCR and FLS techniques being slower ('slow clock') than the current method using actual flight hours as the basis for retirement times. Of course, the benefits of usage monitoring are dependent on how the aircraft is operated.

Descriptors :   *COMPUTER PROGRAMS, *AIRCRAFT MAINTENANCE, *RECOGNITION, *LIFE TESTS, *ROTARY WING AIRCRAFT, DATA PROCESSING, FLIGHT TESTING, MEASUREMENT, AIRCRAFT, DAMAGE, CLOCKS, MONITORING, SYNTHESIS, DYNAMICS, HEALTH, RATES, ACCURACY, COSTS, FEASIBILITY STUDIES, FLIGHT, RETIREMENT, REPLACEMENT, RECORDING SYSTEMS, FATIGUE(MECHANICS), ACCUMULATION, OPERATORS(PERSONNEL), BENEFITS, FLIGHT LOADS, INTERVALS.

Subject Categories : Helicopters
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE