Noise-abatement operational procedures
Recognising that noise is caused by both in-flight operational procedures and ground-based operational procedures, ICAO (2008) proposes a set of noiseabatement operational procedures aimed to target an already existing or predicted noise issue. This includes the use of noise preferential runways, routes and different take-off or approach procedures. Specifically, the literature (Ganic et al., 2015, 2016; Hsu and Lin, 2005; ICAO, 2008) identifies the following:
- • Measures concerning the use of flight departure and approach routings, such as noise preferential routes, dispersed flight tracks, standard instrument departure (SID) and standard arrival route (STAR) procedures and automated arrival and departure procedures
- • Measures limiting the use of runways (i.e. noise preferential runways and displaced thresholds)
- • Measures regarding departure and approach procedures, optimising and breaking down noise distribution and exposure (i.e. noise-abatement departure procedures, descendent profiles, continuous descendent approaches, noise-budget restrictions and others)
Operating restrictions on air traffic
Operating restrictions are recognised to alleviate aircraft noise. These types of restrictions are found to influence airline networks, in terms of frequencies, schedules and routes (Gardiner et al., 2005; Hsu and Lin, 2005; Netjasov, 2012). To this extent, ICAO (2008) encourages states not to apply operating restrictions as their first option but rather to conduct a cost-benefit analysis and adopt alternative strategies to limit noise issues.
According to ICAO (2008), four kinds of operating restrictions can be identified, namely global, aircraft-specific, partial and progressive restrictions. While the first applies to all air traffic at an airport, on the basis of the total fleet noise performance, aircraft-specific restrictions limit movements of only those aircraft categorised as highly noisy. Partial restrictions consider a limited time period during a day or week or the usage of certain runways at the airport. Finally, progressive ones concern a gradual decrease in the maximum level of noise in the long term. There are several examples of operating restrictions that have been applied by airports (Ganic et al., 2015, 2016; Hsu and Lin, 2005; ICAO, 2008; Morrell and Lu, 2000): cap rules, noise quotas, nonadditional rules, the nature of flights, night-time restrictions and airport curfews.
