SAE ARP1279
STANDARD INDOOR METHOD OF COLLECTION AND PRESENTATION OF THE BARE TURBOSHAFT ENGINE NOISE DATA FOR USE IN HELICOPTER INSTALLATIONS (Noncurrent: Jun 1985)
This Aerospace Recommended Practice (ARP) outlines a recommended test procedure, data collection and preparation method for indoor noise tests of a bare turboshaft engine suitable for helicopter installations. It should be recognized that free field measurements are preferable.