Aircraft noise performance evaluation and management

Air transport is among the fastest growing industries and contributes greatly at the regional and national GDP growth by giving momentum at the local and national economy. The importance of air transport in the nowadays society lies in the modified behavioural patterns of travellers which can be summarized in longer range of destinations and increase pressure on travel time. The political changes in air transport market undergone in the USA dur-ing the eighties, followed in the nineties by the European Union, have made air transport even more appealing by large amount of price sensitive passen-ger. The increased concurrence within the market, stimulated by low fare car-riers, has been followed by the use of the frequency as a competitive tool by the incumbent, i.e. the flag carriers. Hence the whole process of deregulation and liberalization globally brought a wide increase in frequency of flights, an average decrease in fares and overall consumer benefit, but also a modifica-tion of the air transport externalities. Air transport as other transport modes impacts the environment at different spatial levels. The impact of air transport emissions at high quota and the use of non renewable resources are the key topics in the discussion on the impact of air transport over the climate change even is well established the small con-tribution of air transport in the production of CO2 in comparison with other transport modes and other human activities. In fact the International Panel on Climate Change IPCC estimates the contribution of aviation carbon di-oxides around the 2 percent. However aviation externalities over the local environment are an important issue which sometimes contributes to strain the relationship between airports and local communities. Aircraft noise has represented the main aviation ex-ternalities since the advent of the commercial jet-era in the sixties. Despite a decrease of around 20 dB in single noise events the problem of airport noise nuisance has slightly decreased due to the traffic growth, the growing envi-ronmental standards which reflects higher economic standards, and especially in Europe the urban sprawling. Most of the airports in use derive from mili-tary airfield once located far away form the city centres. The population growth and the consequent cities development made the cities stretch toward existing airfield making hence these airfield noise sensitive. The externalities of airports which impose costs at local level are not only represented by noise, but also aircraft emission, water pollution, waste dis-posal and vehicle congestion have an increasing weight over the decisions on expanding existing airports or building new ones. Not only noise represents a nuisance for communities located nearby air-ports but also a potential burden for airport growth due to the respect of acoustic limits over residential and industrial area. Airports such as Amster-dam and Dusseldorf had witnessed such policies through the imposition by Governments of an annual limit on the number of movements in order to limit the local communities’ nuisance. Other airports such as the London’s airports and other UK airports have quota count system for night time flights, which means that the maximum number of aircraft movements is limited to a quota and the number of flights depends on the noise characteristics of the aircrafts. Other forms of capacity limitations are based on restrictions on night time movements or restrictions over the noisiest aircraft. All of these techniques reduce the operative capacity of a given airport along with limitations which could stem from reaching the acoustical limits on the areas located near air-ports. Airport noise management is hence a key aspect for all the stakeholders and for managing airport growth.