CHAPTER I
INTRODUCTION
The invention of aircraft enable people to travel to anywhere in the world within hours. The number of aircraft manufactured has progressively increased for the last 50 years, especially for commercial aircraft. Due to the massive numbers of aircraft flying in the sky, the air traffic is significant. As a result more people are concerned about the pollution produced by the aircraft to the atmosphere. Public concerns regarding the emissions around airports first surfaced during the mid to late 60's. The initial regulatory activity was in the USA where the Environmental Protection Agency (EPA), which had been set up under the 1970 U.S. Clean Air Act, published draft proposals by setting limits for carbon monoxide (CO), hydrocarbon (HC) and oxide of nitrogen (NOx) emissions over a standard Landing and Take-off (LTO) cycle.
In regulating aircraft and airports, several compelling interests compete: safety, international commerce, and environmental quality. Of these, safety issues receive perhaps most of the attention, acquiring large headlines in the wake of airplane accidents. But the issue of the effect of airports on the environment and human health has heated up in recent years as public interest and citizen groups contest airport expansion on environmental and health grounds, and the airline and airport industries attempt to meet increasingly stringent regulations in these areas.
Airports are known to be major sources of noise, water, and air pollution. They pump carbon dioxide (CO 2 ), volatile organic compounds (VOCs), and nitrogen oxides (NO x ) into the atmosphere. Toxic chemicals that are used to de-ice airplanes during winter storms are dumped into the waterways. But determining the extent of airplanes' contribution to local, national, and international levels of pollution is difficult, cars and airplanes entering and leaving airports produce roughly equivalent quantities of ozone precursors. Auxiliary power units (APUs),...