Pilot Head and Body Vibration in Response to Main Rotor Track-and-Balance Tuning

摘要

While night vision goggles (NVG) have become an essential part of rotorcraft night flight operations for the military, there has been an increase in the reports of neck strain and neck pain in flight crews using the equipment. The neck is required to support the weight of the NVG on the helmet and is constantly stabilizing the head to counteract the helicopter vibrations. The current flight tests examined the magnitude of vibrations at the pilot's head while tuning or slightly de-tuning the track-and-balance of the main rotor on the NRC Bell 412 as well as measuring the physiological response of the pilot to the resulting vibration levels. While the minimal detuning of the main rotor increased the vibration of the helicopter (by about 0.006g), the increase in vibration at the pilots head was substantial (a 0.01g increase). Physiological measures showed increased heart rate and decreased tactile sensitivity as the helicopter vibration increased. While it is likely that the increased vibration resulting from poor rotor track-and-balance increases the level of neck strain on pilots, further research is required to determine the magnitude of these effects and the maximum safe exposure level.