U.S. Marine Corps Condition Based Maintenance Approach For The CH-53E Helicopter: Five Year Progress Report

Condition Based Maintenance (CBM) is a concept intended to predict component failures based on the real-time assessment of equipment condition obtained from embedded sensors. CBM has the potential to reduce the overall cost of aircraft maintenance, while increasing the operational readiness of the system. It contrasts with traditional Reliability Centered Maintenance (RCM), concepts which employ time–based (periodic), preventive, and reactive maintenance schedules. By employing the CBM concept, which is driven by need, as opposed to a periodic maintenance schedule; unnecessary maintenance efforts can be significantly reduced, thereby reducing the total cost of weapon system support. The U.S. Marine Corps is currently deploying the Goodrich Aerospace Integrated Mechanical Diagnostic System (IMDS) in the CH-53E helicopter fleet. Commercially known as Health and Usage Monitoring Systems (HUMS), IMDS provides rotor trim and balancing solutions, drive system diagnostics, engine performance checks, and data required to perform flight regime recognition for structural usage monitoring. The combination of a periodic maintenance environment coupled with the deployment of IMDS make the Marine Corps CH-53E helicopter fleet a logical proving ground for the Future Logistics Agency CBM+ doctrine. In January 2005, the CH-53E IMDS Integrated Product Team (IPT) re-convened for the purpose of implementing CBM principles via IMDS. Rotor balance, engine performance and usage, mechanical diagnostics, and structural monitoring Working Groups compiled near and long term plans to leverage respective health and usage monitoring tools in order to gain CBM credits. These plans were subsequently presented at the 2006 American Helicopter Society Forum [Ref. 1]. Several key activities such as scheduled maintenance reduction, overhaul and removal extensions, and improved readiness were identified and a systematic integration approach documented. As CBM implementation proceeded, a number of unforeseen programmatic, technical and process challenges developed. This paper will address the progress and challenges encountered within the initiatives presented in 2006, and will provide updates to the activities identified for implementation during the last five years.