HC Deb 27 November 1969 vol 792 c142W
Mr. Johnson Smith

asked the President of the Board of Trade, in view of the progress made in the development of quieter aircraft engines, if he will take steps to provide for a retrofit programme in the United Kingdom to reduce aircraft noise while the older jet aircraft are completing their working life.

Mr. Goronwy Roberts

A retrofit programme for current aircraft is more difficult technically and economically than the quietening of future types of aircraft. This matter is being examined internationally but studies so far suggest that cost would be very heavy in relation to any likely benefit in noise reduction.