Helicopter Vibration Health Monitoring Systems Featuring Engine Vibration Monitoring

Airbus Helicopter provides Health and Usage Monitoring Systems (HUMS) offering a broad range of functions like on-board Rotor Tuning, Vibration Health Monitoring and Engine Vibration Monitoring (EVM) as feature of vibration monitoring. For the latter, Airbus Helicopters cooperates with SAFRAN Helicopter Engines in the frame of data collection, data processing and data transfer to assure the maximum of benefit for the customer. A clear objective is to provide HUM system compliant with operational requirements and guidelines from UK CAA, CAA Norway, industry associations like SAE and working groups like IHST. Classical vibration based health algorithm require information from analogical speed sensors for signal processing methods like time synchronous averaging and feature extraction. Airbus Helicopters proposes an approach without analogical speed interface, but extracting necessary information from the vibration and digital speed signals. This technique makes use of the speed interface which is part of the baseline helicopter and thus omits any electrical modification of the parts. This paper presents the approach used by Airbus Helicopter in cooperation with SAFRAN Helicopter Engines in the area of feature extraction and condition indicator computation using vibration signals and digital information from the helicopter avionic system HELIONIX.