STUDY TO ESTABLISH REALISTIC ACOUSTICAL DESIGN CRITERIA FOR FUTURE ARMY AIRCRAFT

A study is reported of aircraft noise and its effect on Army operation and utilization of equipment. A sound pressure level measurement program was carried out on 12 Army aircraft specifically, the L-20, L-23, U-1A, H-13, H-21, H-23, H-34, H-37, HU-1A, YHC-1A, Doak 16 and Vertol 76 Aircraft. A study was also made of the effect of aircraft noise on Army aircraft operations as limited by the noise environment to which pilots are exposed, and performance limits which might be imposed on the aircraft by additional soundproofing treatments. It was concluded that MIL-A-8806 ASG, the Military Specification for noise levels in aircraft should be amended for Army Aircraft during normal cruise power by the addition of tabular data on frequency bands and acceptable noise level at normal cruise power.