A Simulation Model To Investigate the Impact of Health and Usage Monitoring Systems (HUMS) on Helicopter Operations and Maintenance

The objective of this paper is to show how an analytical simulation model of the helicopter maintenance and operations environment can be used to analyze the effects of health and usage monitoring systems (HUMS) technology on aircraft readiness and maintenance workload. The development of the model is described and operational scenarios are investigated including operations with and without HUMS. In particular, the effect of maintaining airframe vibrations below a specified threshold using continuous rotor track and balance is investigated. Also, the effect of HUMS false alarm rate is examined. Results from the simulation indicate that phase maintenance is a major maintenance bottleneck at the operational level and can have a substantial impact on operational availability. Model results also show that efforts to maintain very low airframe vibration levels can become cost prohibitive and that a high false alarm rate for HUMS can result in significant increases in maintenance costs as well as lower operational availability.