Maintenance Planning and Spare Parts Provisioning for a Small Unmanned Aerial System

This paper details a maintenance model for the Silver Fox Small Unmanned Aerial System. The system is comprised of a number of mission critical, modular components as well as a number of mission enhancing components. A typical system is deployed for 180 days and consists of one aircraft, a spares kit, and a hangar queen aircraft. A discrete event simulation model is developed to evaluate the effects of maintenance planning decisions and spare parts provisioning on aircraft availability. The model explores using both the parts from the spares kit and cannibalized parts from the hangar queen in order to keep the aircraft availability high. When a part fails, it is sent back to the United States for refurbishment which takes a certain amount of time. We investigate the effects of spare parts provisioning, allowable maintenance time, and refurbishment lead time on several metrics. We show that changes in these policies have a significant impact on aircraft availability and capability.