VIBRATION CHARACTERISTICS AND FAULT ANALYSIS OF HELICOPTER PEDALS

Zhang Xiamei, Yu Zelian, R.T. Lotoa

ABSTRACT : Helicopters have numerous rotating components, and the vibrations generated during flight are significant, which negatively affects the pilot’s flight control and physical and mental health. Therefore, vibration reduction and noise attenuation of helicopters are crucial research areas. Pilots complete flight missions through the flight control system, and the usability and comfort of the control system directly affect flight quality and safety. For a certain type of helicopter where excessive pedal vibration caused a “pedal-kick” fault, this paper employed a real-time vibration monitoring system to test and monitor the helicopter pedal vibration. Based on the flight test data, a spectral analysis was conducted on the helicopter pedal vibration signal to determine the abnormal vibration frequency. Then, by combining the comfort decrease limits and evaluation criteria for whole-body vibration exposure, the helicopter’s aft cabin pedal vibration was diagnosed for faults. The source of the pedal “kick” vibration was accurately located, and after implementing relevant measures, the fault was successfully resolved.

Keywords : Real-time vibration monitoring system, helicopter tail rotor control system, pedal, comfort decrease limit, spectral analysis