Environmental Engineering Reference
In-Depth Information
Commission, 2002). The most commonly used approach to measuring noise exposure
involves the calculation of the average amount of noise exposure experienced at a par-
ticular location over a specific period of time (eg 8 hours, 12 hours or 16 hours) and
is a function of the number of aircraft movements and the noise made by each. A
number of reports compare these noise exposure measures with the results of social
surveys relating to levels of perceived disturbance in areas of different noise exposure.
Some argue, and it is evident from noise complaints received by airports, that as traf-
fic has increased and aircraft have become quieter, the frequency of exposure is becom-
ing a more important cause of nuisance (Janic, 1999). All this would suggest that
conventional noise-assessment metrics alone may not be adequate as an indicator of
disturbance around airports.
T
HE
SUSTAINABLE
DEVELOPMENT
CHALLENGE
Increasing global affluence is likely to lead to growth in air traffic demand. In part,
this will be associated with the development of a global society, increasing trade, chang-
ing patterns of consumption and the maintenance of increasingly disparate social and
family networks. A significant additional factor will, however, be an increasing demand
for leisure travel.
These same drivers that fuel demand will also be associated with an increasing
expectation of quality of environment, increasing concern for public health and a
declining tolerance of nuisance, all of which will lead to increasing opposition to
growth. The problem posed by this paradox is made worse by the fact that current
forecasts indicate, as will be explained, that the anticipated growth in air traffic
demand for the next 20 to 30 years will continue to outstrip improvements in aircraft
noise technology. The result will be that the noise climate around many airports
throughout the world is likely to deteriorate in the future. The sustainable develop-
ment challenge for the air transport industry is to meet increasing demand for air
travel, while at the same time constraining or even reducing the number of people
exposed to 'unacceptable levels' of nuisance from aircraft noise.
The control of aircraft noise
A wide variety of measures are used to minimize the number of people exposed to
aircraft noise and, hence, the level of nuisance they face.
Technological improvement
There is no question that significant improvements have been made in aircraft engine
and airframe technologies over the past 20 to 30 years that have dramatically reduced
the level of, and the area of exposure to, noise generated by modern aircraft. How-
ever, it would appear that the potential for further improvement is becoming more
difficult. No step change in technology is on the horizon, and it can be anticipated
that any such development would be exceedingly costly.
Even when new technologies have been developed, it takes many years for certi-
fication and airworthiness approval mechanisms to take effect. It then takes even longer
for aircraft to progressively enter the airline fleet, if only because of the very high costs
