Description / Abstract:
Test procedures are described for measuring noise at specific
receiver locations (passenger and cargo doors, and servicing
positions) and for conducting general noise surveys around
aircraft. Procedures are also described for measuring noise level
and directivity at noise source locations to facilitate the
understanding and interpretation of the data.
Requirements are identified with respect to instrumentation;
acoustic and atmospheric environment; data acquisition, reduction
and presentation, and such other information as is needed for
reporting the results.
This document makes no provision for predicting APU or component
noise from basic engine characteristics or design parameters, nor
for measuring noise of more than one aircraft operating at the same
time.
No attempt is made to suggest acceptable levels of noise or
suitable subjective criteria for judging acceptability. ICAO Annex
16 Volume I Attachment C provides guidance on recommended maximum
noise levels.
Purpose
This aerospace recommended practice (ARP) describes standard
conditions and procedures for measuring, analyzing and reporting
noise resulting from operation of on-board APUs and associated
equipment of aircraft undergoing servicing.