Operational Evaluation of a Health and Usage Monitoring System (HUMS)

Abstract

Abstract : This report describes the results of a research program to evaluate structural usage monitoring and damage tolerance methodology using data collected concurrently during a helicopter flight program. The helicopter (a Bell Model 412 equipped with a Health and Usage Monitoring System (HUMS) and data recorder) was operated by Petroleum Helicopters Inc. (PHI) during the 1996 Summer Olympic Games in Atlanta, Georgia, under the FAA's Project HeliSTAR. The mission was referred to as the Atlanta Short Haul Mission (ASHM) and involved many short flights to provide pick up and delivery service at the Olympics. The usage data collected for the ASHM was used to perform fatigue life calculations and damage tolerance evaluations on selected rotor system components know as Principal Structural Elements (PSE's). The usage data from the ASHM were compared to certification data and to data from a previous study for a mission called the Gulf Coast Mission (GCM) which involved primarily long cruise flights. Although the usage was more severe for the ASHM than the CGM, the results of the comparison showed that usage monitoring would provide benefits in extending retirement times or inspection intervals, compared to certification, especially if high/low altitude effects were considered. In addition to usage monitoring evaluations, guidelines for HUMS certification are discussed along with potential economic benefits and simplified mini-HUMS approaches to provide low cost systems with high paybacks.