Difference in airport noise calculation procedures between AERC Model and ECAC DOC.29

This paper describes a result of examination on differences in airport noise calculation procedures between AERC Model and ECAC DOC.29. AERC Model has been basically developed as a tool for calculating noise contours based on a noise evaluation method specified in the Japanese noise guideline "Environmental Quality Standard for Airport Noise," which requires taking account of noise contributions due to aircraft ground operations such as taxi, engine run-up and using APU on the apron in addition to aircraft flight movements. On the other hand, ECAC DOC.29 is a guidance material describing an aircraft noise prediction method as a best practice for European countries. Note that AERC Model has a modified version almost complying with ECAC DOC.29, while ECAC DOC.29 cannot be used in place of AERC Model because ECAC DOC.29 is not possible to consider aircraft ground operation noise. Now, the two models must calculate flight noise contributions equally each other, because those are commonly based on the energy-based segment noise modeling concept. But, when comparing noise calculation procedures in detail, we find some differences between the two such as those in the way of segment division, thrust interpolation, EGA calculation, flight path dispersion, sound directivity behind the takeoff roll segment. This paper discusses influences of such differences on noise calculations.