With reference to the letter by John Murphy 'an argument built on a fiction' (Chronicle, July 31), I would like to take the opportunity to clarify a number of facts concerning the future growth of Heathrow.
A third runway will not go ahead, unless air quality is better than today, there is no more noise than in 2002 and there are improvements to public transport to prevent congestion. This is not growth at any cost; this is growth within strict environmental limits.
Aircraft are getting cleaner and quieter and there is no doubt that this trend will continue - especially with the current record prices for oil.
In fact, all the major aerospace manufacturers, including Airbus and Boeing, have committed to a target of a 50 per cent reduction in noise levels from year 2000 levels by 2020.
Any suggestions that the figures were 'fabricated' or 'fiddled' are wholly inaccurate.
Modelling and forecasting are necessarily uncertain, but can still provide a useful indication of likely future impacts.
In forecasting a fleet mix for 2030, BAA is making a best estimate of what kind of technology will be available at that time. Most airliners have approximately a 20-year life in front-line service - it follows that the oldest aircraft types in service in 2030 will not have been delivered yet and the newest neither designed nor built.
The aviation industry is always changing and the proportion of four-engined aircraft versus two-engined aircraft is reducing as new aircraft like the Boeing 787s are introduced into the Heathrow fleet.
BAA's fleet mix assumptions reflect our most recent understanding of the industry at the time. When deciding on the final figure of six per cent, BAA spoke to its largest long-haul airline partners to test this assumption and the airlines confirmed this number.
Subsequently, the purchasing patterns of our major airlines have reaffirmed this assessment.
Most importantly, the environmental limits set out by the Government are absolute and non-negotiable.
If slower fleet replacement or slower advancement of new technology means that noise and air quality emissions do not reduce as quickly as predicted, then airport capacity will grow more slowly than predicted.
We would expect planning authorities to make the Air Transport White Paper noise and air quality limits a legally binding condition of any possible future planning consent.
DAMON HUNT Head of Media, BAA.