Environmental Engineering Reference
In-Depth Information
Source:
Birch, 2000
Figure 10.1
Aircraft noise
any other. The long-term future has the potential to offer revolutionary solutions
that may significantly reduce the environmental burden of the aviation industry. For
these solutions to play a part in the industry of the future, a number of key factors
need to be considered. First, drivers need to be put in place to stimulate the industry
to develop these revolutionary concepts. This motivation could come from a wide
range of sources - from environmental concerns and legislation to increased aviation
fuel prices. Second, the ability to develop from a concept to a product, and third,
the opportunity to make changes (Birch, 2000). A variety of alternative solutions are
currently being evaluated, from innovative engine/airframe configurations, active
laminar flow
2
and advanced combustion technologies to alternative fuel systems.
The ability of these technologies to meet expectations, individually or in combina-
tion, will determine the future effect of aviation on the environment and, ultimately,
the part it will play in the transport system of tomorrow.
Noise
Noise has traditionally been a key design issue for air transport systems, especially
for communities around airports, and is subject to international noise legislation.
The industry has cut noise levels by 20 decibels (dB) during the last 30 years (Air
Transport Action Group, 1999, p11), as is shown in Figure 10.1.
Despite the growth in air traffic in recent years, noise exposure to communities
living in close proximity to airports has been decreasing. This has been due to the
retirement of older, noisier aircraft and the development and incorporation of noise-
reducing technologies within the remainder of the fleet. However, in the coming years
it is expected that noise levels will start to rise again as the continued growth of the
fleet will outweigh further reductions in the average noise levels - see Figure 10.2
(Walsh, 2000).
Future noise control must be achieved by a combination of source noise reduc-
tion, developments in operational procedures, such as take-off and landing corri-
dors, and improved land-use planning systems.
