Sir - While I agree wholeheartedly with the need for an up-to-date transport policy, your statements on noise and limits contained in the Comment article "Sound of silence" (Flight International, 18-24 September) need to be challenged. Any reduction achieved in noise levels is to be welcomed, but whether a 3dBA reduction on the flightpath to the London airports is to be noticed, is a matter of conjecture.
The fines which are now imposed as penalties on noise-infringement levels are inadequate - either as a revenue source, or as a deterrent. Persistent offenders will merely accept the fines and add them to the cost of the fares which they charge.
Secondly, the position of noise-monitor arrays capture only the minority of those breaking the limits.
K J ABNETT
Federation of Heathrow Anti-Noise Groups
East Molesey,Surrey, UK
Source: Flight International