The effects of airborne vibration on human body vibration response

Aircraft ground operations and maintenance personnel can be exposed to whole-body vibration via the airborne transmission of acoustical energy. The purpose of this study was to characterize human body vibration response during exposures to airborne vibration generated by military fighter aircraft during high-power ground engine runs. Miniature triaxial accelerometers were mounted on the head (bitebar), chest, spine, and lower leg of the subject. Measurements were made for selected locations along a line parallel to the longitudinal axis of the aircraft at specified engine-power settings. The highest accelerations occurred in the fore-and-aft (X) chest response. One-third-octave analysis showed a distinct peak in the chest between 50 and 100 Hz not observed in the noise levels, strongly suggesting the presence of a chest resonance. These peaks increased as the subject moved aft of the aircraft. While the noise levels also increased, it was difficult to determine a relationship between acceleration and noise without additional data due to differences in the results between power settings. The subject did report an increased sensation of vibration in the upper torso, which coincided with the increased noise levels. These data will be used in the development of human airborne vibration exposure guidelines.