Sikorsky Health and Usage Monitoring System (HUMS) Program

Sikorsky Aircraft has a program in place for helicopter Health and Usage Monitoring Systems (HUMS). This includes both the development and fielding of a HUMS for the S-76 and S-92 helicopters, and support of operator installed HUMS. The paper discusses the background and reasons for developing the Sikorsky HUMS2. In response to Sikorsky requirements, the hardware and software for this HUMS have been developed by GEC-Marconi, based upon their experience in fielding their Integrated Health and Usage Monitoring System (IHUMS). The Sikorsky HUMS2 includes airborne processing for most functions combined with a ground station which provides extensive capability including uploading and downloading of data, display of faults detected on aircraft, trending of pertinent parameters to guide the maintainer in planning his maintenance actions, and the ability to evaluate in depth the fault indications found by the HUMS2. HUMS2 can provide output to a combined cockpit voice and flight data recorder (CVFDR) with solid state memory. The functions in HUMS2 include basic operational usage, structural usage, rotor track and balance, drive train monitoring, automated power assurance, and exceedance monitoring. The implementation of these capabilities is discussed. In addition, Sikorsky has set up a program to support those operators flying S-61 and S-76 helicopters equipped with HUMS. This ongoing cooperation with the operators has provided both parties with correlation between the faults indicated by HUMS and the evidence found during teardown of the gearboxes to help increase the confidence in the fielded HUMS.