The DLR Project "Quiet Air Traffic"

Abstract

Aircraft noise- especially during the night - is an urgent environmental problem. It will become more and more critical in near future because the ongoing growth of air traffic will force an increase of the noise load around airports which cannot be overcompensated by the noise reduction techniques for airplanes currently available. Following ICAO’s “Balanced Approach” there are three different ways to reduce the aircraft noise load in the vicinity of an airport: (1) Noise reduction at the source (e.g. reduction of engine- and airframe-noise), (2) operational measures (e.g. noise abatement flight procedures) and (3) regulatory and planning measures to mitigate noise (e.g. noise depending landing fees). Whereas the the technical potential for the reduction of engine- and airframe noise can be realized fully only in the long term, operational and regulatory measures can be brought in effect already in short and medium term. However an effective abatement of aircraft noise cannot consist just in a technical and operational reduction of the physically measurable sound. Much more it must take into account the physiological and psychological effects of noise on people. In particular, our knowledge of the effects of nightly aircraft noise needs to be improved considerablely. Furthermore modern aircraft noise prediction models must be developed as tools for the development and analysis of any noise mitigation measure: In practice aircraft noise cannot be be measured under controlled conditions without exploding costs. Taking into account all these aspects of medicine, technical design and land use planning a project dealing with aircraft noise reduction must be of interdisciplinary nature tomake sure that existing relationships between different approaches for noise reduction and hence synergy effects are taken into account adequately. Within the project „Quiet Air Traffic“ and its successor „Quiet Air Traffic II“ the DLR has made use of such an interdisciplinary approach - integrated into national and international networks. The paper gives an overview on the results obtained within both projects during the time period from 1999 to 2007.