Accession Number:



Vibration Exposure Characterization and Health Risk Assessment of the MH-65D Dolphin

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Technical Report,01 May 2017,31 Dec 2018

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711 Human Performance Wing Wright-Patterson AFB United States

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This study characterized and assessed aircrew vibration during operation of the MH-65D Dolphin owned and operated by the Coast Guard Helicopter Interdiction Tactical Squadron HITRON located at Cecil Field, FL. The study was part of a collaboration between the Army Public Health Center and the Air Force Research Laboratory, and was funded by the National Defence Center for Energy and Environment. The ISO 2631-1 1997 was used as the guideline for the assessments. Triaxial accelerations were collected at the floorseat base, seat pan and seat back interfaces, and helmet pilot only at the pilot, copilot, gunner, and swimmer stations. Data records were collected by aircraft task and associated flight test conditions. All stations showed a major spectral peak in all three directions at approximately 23.5 Hz that was associated with the blade passage frequency of the aircraft. A smaller primarily vertical peak was also observed around 6 Hz that was associated with the propeller rotation frequency. At the pilot helmet, the vertical peak around 6 Hz could be quite substantial, depending on the flight test conditions. Based on the ISO 2631-1 guidelines, comfort reactions primarily ranged from being a little uncomfortable to fairly uncomfortable. Based on the seat pan point vibration total value ISO 2631-1, the level flight vibration was associated with the potential for health risk in less than 8 hours of daily flight operation at all stations the lowest exposure durations and highest weighted vibration levels occurred at the highest airspeed 140 KIAS, except at the mid cabin gunner station. The copilot and swimmer stations showed decreases in the exposure durations with increasing airspeed. Health risks were likely in less than 8 hours at the swimmer station at the highest airspeed 140 KIAS.

Subject Categories:

  • Medicine and Medical Research
  • Helicopters
  • Mechanics

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