Environmental Impact of Aviation

Environmental problems that people face globally are too serious and too complex to be ignored. They may be of local or global concern and may involve trans-boundary issues of international significance. They may affect different communities, population groups and countries in different ways. That is why environmental impact assessments are being used increasingly in decision-making by national authorities and international bodies.

Aircraft emissions were recognized as a problem for the aviation industry in the early 1980s, when interest in the acid rain and ozone depletion increased. Though aviation contributes only 3% of the pollution from all transportation sources, the industry has been productive with regards to environmental issues and has introduced its own regulatory standards for both noise and pollution.

There are four main types of emission from aircraft engines: carbon monoxide (CO), unburned hydrocarbons (UHC), carbon dioxide (CO₂) and nitrogen oxides (NOx). CO and UHC are produced in small quantities and are not considered significant emissions. CO₂ is produced directly from the combustion of fuel. Modern engines have better fuel economy and hence produce less CO₂ than early jet engines, or engines built without regard for efficiency.

NOx is the most significant emission. During an average flight, 80% of the pollution is NOx, produced by heating air to high temperatures as it passes through the engine combustion chamber.

ICAO intends to reduce its certification standard for emissions by 20%. Within the European Community, additional legislation is expected to reduce the ICAO limit by 33%. These decisions forced engine manufacturers to improve their engines to meet the stricter standards.

We are permanently exposed to noise levels, which endanger our health and quality of life. Nowadays noise is becoming one of the major pollutants: the constant noise in the street, and even inside buildings, playing loud music, noise from transport means etc. People’s activities produce aggressive noises that cause an enormous stress on the nervous system. Pollution knows no boundaries whether it is airborne or waterborne; it is the cause of health hazards for entire population of the world.

Aircraft noise has decreased significantly since jet aircraft were first introduced. The International Civil Aviation Organization (ICAO) has established three categories of aircraft certification. Stage 1 aircraft, the first and noisiest, have all disappeared from service. The majority of aircraft in service now are stage 2, including the Tupolev 134-A and the older DC-9 and Boeing 737-200. Under ICAO ruling, stage 2 aircraft were to be phased out of service by April 2002, unless modified to meet the much stricter stage 3 noise requirements.

In October 2000 the ICAO’s Committee for Aviation Environmental Protection (CAEP) reviewed the aircraft noise certification standards for transition to Chapter 4, made efforts to agree a new international standard for aircraft noise reduction. The air transport industry is anxious to preserve its investments in Chapter 3 aircraft while pushing for a single global standard that will prevent the proliferation of regional noise limits like the European Union’s hushkit ban. CAEP recommended a new, Chapter 4 standard 10 dB below current limits, effective from 1 January 2006. The EC’s regulations effectively freeze the number of hushkitted aircraft (hushkits may offer technical compliance with Chapter 3) able to serve EU airports, barring the 2000 or so Chapter 2 aircraft already hushkitted or available for hushkitting which might otherwise be able to fly into Europe after being made Chapter 3 compliant. CAEP’s approach to noise mitigation would improve land use planning and control and encourage the application of new noise abatement operating procedures.

Boeing and Rolls Royce have come together to conduct a noise reduction flight test program. They were able to demonstrate noise levels significantly below those of a standard 777, already one of the quietest aircraft in service. A spokesman for Boeing says: ”Combined with air frame noise reduction and engine redesign, the new technologies can be incorporated on a new aircraft or as a retrofit”.

To survive mankind must treat environment seriously ensuring its safety through using the developed world’s experience, raising environmental awareness and improving legislative control of environmental management.

Note: were to be phased out of service – мали бути вилучені з експлуатації – должны были быть выведены из эксплуатации

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