The Certification Of A CBM Test Bed For Playback Of Recorded Aircraft HUMS Data

The US Army has been developing and fielding Digital Source Collectors (DSC), also known a Health and Usage Monitoring Systems (HUMS), on Army Aircraft for the last 10 years. During this process the testing of the HUMS software for airworthiness has become a very challenging but needed requirement. The normal test involves coordinating the delivery of the Original Equipment Manufacturer (OEM) software to be tested, scheduling test resources, scheduling with the PM a test aircraft (A/C) and then conducting and subsequently analyzing the test data. During many test events, the outcome of the test was that the software failed the test, sending the process back to the start. Some testing sequences have required several test cycles and have resulted in the delay of over 6 months before the software was deemed to be satisfactory for fielding. The biggest factor in this process has been the availability of aircraft and the lack of fidelity in bench testing to accurately model the A/C to ensure a successful aircraft test outcome. Most OEMs use lab equipment to generate the required signals to stimulate the DSC under test, but once the test was replicated on an actual aircraft, issues were found in the process.