A computer system for aircraft flyover acoustic data acquisition and analysis

Abstract

A mini‐computer‐based system housed in a mobile trailer was designed for field measurements of aircraft flyover noise. The system was used to accomplish recent Federal Aviation Regulation Part 36 noise certification testing for the new Boeing model 757 and 767 aircraft. The multi‐user system performed acoustic and telemetered data acquisition, analysis, and data storage. All data were made available to online color monitors and on hardcopy. One‐third octave band acoustic data were acquired and analyzed via microcomputer controlled digital frequency analyzers. Ground weather data and telemetered data, which includes upper air weather and airplane position and performance information, was received, stored and displayed automatically. By integrating all of the data, fully corrected acoustic time histories, spectra, and EPNL values were calculated within minutes of an airplane flyover. Online data output were used to make test operational decisions and evaluate aircraft noise level predictions. This computer system increased test efficiency by providing high quality data to personnel for real time decision making.