Evaluate Noise Level For Airliners

In the 21 st century's, the development of the domestic large aircraft is a major decision-making, have important sense about the party central committee and the state council. "Commercial development, airworthiness first" is the fundamental philosophy of civil aviation industry. With the development of civil aviation industry in our country, the noise impact on the local resident's life become more and more obvious. Noise certification of the domestic large aircraft is imminent.This article evaluates noise level for airliners by analyzing the ICAO CH4-7.Firstly, this thesis researched the large aircraft noise limits, the choice of reference noise measurement point and the relative test procedure, studied the ICAO CH4-7,compared with the CH3 and CH4, researched and analyzed the method of compliance demonstration for CH4-7 airworthiness regulation. According to the condition that the maximum noise level should satisfy, and gave some example for method validity.Next, this article based on CH4-7 that developed noise airworthiness compliance system thought using VB language, and evaluated noise level separately on the in-service models and new models. Specifically for the C919, that combined with its the new noise data of different model for competing aircraft, that carried out noise airworthiness compliance. This work has guiding sense to noise airworthiness compliance and noise evaluation of the domestic large aircraft C919.Finally, I used the latest noise data, mapped a series of noise contour maps of the C919's competing aircraft, and its smoothing and accuracy are improved obviously.Not only provided technical support for C919, but also provided reference for the professional staff of airworthiness certification, manufacturer of aircraft and airlines.