A study on the necessity of evaluating aircraft ground noise emissions around airports

In Japan, when the aircraft noise assessment index was changed from WECPNL to Lden in 2013, ground noise was also included in the assessment. Compared to flight noise, ground noise has a lower power and is often observed as an unclear and long-lasting level fluctuation at observation points that are some distance away from the source. Therefore, it is often difficult to treat ground noise as a target for measurement and evaluation. We have been surveying ground noise exposure through constant monitoring and short-term surveys around Narita Airport and other airports in Japan. The results suggest that engine run-up with high generated power and taxiing on taxiways close to residential areas account for a large contribution to the total ground noise energy, while APU with low power and unclear level fluctuations tend to have a very small contribution. There may be no need to necessarily include APU noise with very small observed levels in the evaluation.