A comprehensive noise survey of the S-70A-9 Black Hawk helicopter.
OBJECTIVE
This paper reports the results of a comprehensive noise survey of the Sikorsky S-70A-9 Black Hawk helicopter environment and provides an assessment of the hearing protection devices worn by Australian Army personnel exposed to that environment.


RESULTS
At-ear noise levels were measured at 4 positions in the cabin of the Black Hawk under various flight conditions and at 13 positions outside the Black Hawk under various ground running conditions using the Head Acoustic Measurement System (Head, GmbH). The attenuation properties of the hearing protection devices (HPDs) normally worn by aircrew and maintenance crews (the ALPHA helmet and the Roanwell MX-2507 Communications headset) were also assessed. At-ear sound pressure levels that would be experienced by personnel wearing their normal HPDs were determined at the positions they would normally occupy in and around the aircraft.


CONCLUSIONS
Results indicate that HPDs do not provide adequate hearing protection to meet current hearing conservation regulations which allow a permissible noise exposure of 85 dB(A) for an 8-h day.
King
R B
RB
Aeronautical and Maritime Research Laboratory, Fishermens Bend, Victoria, Australia.
Saliba
A J
AJ
Brock
J R
JR
D000162:Acoustics; D000337:Aerospace Medicine; D000401:Aircraft; D001315:Australia; D004430:Ear Protective Devices / Q000592:standards*; D006306:Health Surveys; D006801:Humans; D008452:Maximum Allowable Concentration; D008889:Military Personnel; D009623:Noise, Occupational / Q000517:prevention & control* / Q000706:statistics & numerical data*; D016273:Occupational Exposure / Q000032:analysis* / Q000517:prevention & control*; D016272:Occupational Health; D013018:Sound Spectrography; D013997:Time Factors