Air transportation plays a substantial role in world economic activity, and
society relies heavily on the benefits associated with aviation. The aviation
industry includes suppliers and operators of aircraft, component manufacturers,
fuel suppliers, airports, and air navigation service providers. Its customers
represent every sector of the world's economy and every segment of the world's
The commercial sector of the industry is highly competitive, consisting in
1994 of about 15,000 aircraft operating over routes of approximately 15 million
km in total length and serving nearly 10,000 airports. In 1994, more than 1.25
billion passengers used the world's airlines for business and vacation travel,
and well in excess of a third of the value of the world's manufactured exports
were transported by air. The aviation industry accounted for 24 million jobs
for the world's workforce and provided US$1,140 billion in annual gross output.
By the year 2010, aviation's global impact could exceed US$1,800 billion and
more than 33 million jobs (IATA, 1994, 1996).
The 1944 Chicago Convention, to which 185 countries are now party, established
the International Civil Aviation Organization (ICAO) as the United Nations'
specialized agency with authority to develop standards and recommended practices
regarding all aspects of international aviation-including certification standards
for emissions and noise. These standards are published as Annexes to the Convention
and are adopted by the ICAO Council, which is composed of 33 member nations
elected by the entire ICAO membership. Individual countries either adopt ICAO
standards or file differences with ICAO.
Since 1977, ICAO has promulgated international emissions and noise
standards (ICAO, 1993a,b) for aircraft and aircraft engines that apply to all
member states. ICAO, through its Committee on Aviation Environmental Protection
(CAEP), has reviewed and revised these standards when warranted and has developed
operational policies and procedures to mitigate further the environmental impacts
of civil aviation. ICAO has also developed broader policy guidance on fuel taxation
and charging principles that have relevance in the emissions context. In addition
to the harmonization achieved through ICAO, international flights are subject
to bilateral air service agreements between individual countries.
Figure 1-2: Impacts of aviation on the
The commercial airline industry, though predominantly privately
owned and managed, must rely on airport infrastructure and air navigation services
that the industry neither owns nor controls. The overall growth of air traffic
and the capacity limitations of airports and air navigation services have introduced
congestion as a challenge for aviation. This congestion causes delays, introduces
unreliability or inefficiencies for all system users, and produces considerable
extra energy consumption and emissions. During 1996, for example, 15.4% of flights
in Europe incurred an average delay of 16.7 minutes. In the United States of
America, the average delay for domestic departures was 7.2 minutes.
Growth in demand for aviation averaged about 5% per year for the period 1980-95.
The industry expects demand to continue to rise, though not monotonically. Aviation
growth may be estimated reasonably well in the near term, but forecasts are
subject to greater uncertainty beyond a 5-10 year period because of changes
in factors such as the real cost of air travel, economic activity, new market
opportunities, world disposable income trends, world political stability, tourism,
and air transport liberalization.
An aircraft is a major investment, with a useful economic life of 25 years
or more. Operation of an aircraft includes airframe and engine performance.
The performance of an aircraft must address the overriding issue of safety,
as well as mission or performance efficiencies, economics, and environmental
objectives. ICAO is the responsible organization to ensure that such objectives
are met on an internationally harmonized level as far as possible.