Rotor Track and Balance Cost Benefit Analysis and Impact on Operational Availability

This paper reports the preliminary results of an on going study. The study is concerned with the operational benefit of the Integrated Mechanical Diagnostics Health and Usage Management Systems (IMD HUMS) rotor track and balance (RTB) functionality, based on the considerable experience gained over the last few years. This study quantifies the benefits using IMD HUMS for RTB in terms of aircraft availability, functional check flight hours and maintenance man-hours used for rotor track and balance evolutions. Experiments are conducted using a discrete event simulation model. Input parameters governing the distributions of maintenance action inter-arrival times are estimated with data from the Decision Knowledge Programming for Logistics Analysis and Technical Evaluation (DECKPLATE), Naval Aviation Logistics Command Management Information System (NALCOMIS), Draper Laboratories and squadron experiences. Output analysis is focused on maintenance policy and the number of IMD HUMS configured aircraft in the squadron. Preliminary results suggest that flight time used for functional check flight (FCF) can increase with increasing number of IMD HUMS configured aircraft due to the increased need for rotor-tuning events. Further, even with the increased number of rotor-tuning events the total amount of elapsed maintenance time (EMT) spent on rotor track and balance will decrease. Results also indicate a decrease in FCF time and greater gains in EMT when maintenance policy is adjusted to suit a continuous monitoring system.