§ Mr. Varley
asked the Minister of Aviation what research is going on, or is contemplated, to ensure that when supersonic air liners are regularly operational the noise from them is kept within tolerable limits.
§ Mr. Stonehouse
Fundamental work on the subjective effects of sonic bang type noise is in progress at the National Physical Laboratory and at the Medical Research Council's Applied Psychology Research Unit. Field work on a rather larger scale is contemplated, if a method of simulating sonic bangs using explosives can be perfected by the Explosives Research and Development Establishment. Further live tests with supersonic aircraft are under consideration. At the same time theoretical work is continuing at the Royal Aircraft Establishment to increase our knowledge of the effects of174W atmospheric variations and ground reflection effects on the type of sonic bangs produced under different conditions and by different aircraft.
As regards engine noise, the Concord engine development programme includes work both in industry and at the National Gas Turbine Establishment designed to ensure that noise is kept within tolerable limits. Various forms of noise suppressors for incorporation in the engine are being investigated.
Other programmes of work on these subjects are in hand in France and the United States and information is exchanged freely in most areas.