HC Deb 11 July 1955 vol 543 cc1577-8

At the end of Questions—

Mr. Maudling

I will, now Mr. Speaker, make the statement I undertook to make in reply to Question No. 24.

Special investigations carried out under the auspices of the Royal Aircraft Establishment confirm that pressures capable of causing damage can be caused by shock waves from aircraft travelling at or above the speed of sound. The extent of the pressure diminishes rapidly with the height of the manoeuvre and from heights above 30,000 feet the effect should not be serious. More precise data will be available as experience grows.

Manoeuvres at supersonic speeds are essential for the development of new types of aircraft, for the testing of production aircraft, for the training of pilots, and for realistic exercises. Neither I nor my right hon. Friends the First Lord of the Admiralty and the Secretary of State for Air can, therefore, accept a complete ban on supersonic flying over these islands. We are, however, revising the present measures of control in the light of these investigations so as to reduce disturbance and the risk of damage to a minimum.

The measures we have in mind for research establishments and contractors will have the effect of diverting most supersonic flying out to sea, though some exceptions to this will always be necessary. But supersonic flight over land, when permitted, will be so regulated as to minimise, so far as possible, consequent disturbance to the public.

In particular, I propose to issue an instruction to contractors and Ministry of Supply establishments that supersonic flying is not to take place below 30,000 feet except in special circumstances where this is necessary for the development programme, and then only with the authority of my Ministry.

Broadly similar steps are being taken by the Service Departments and by Commonwealth and Allied Air Forces serving in the United Kingdom, although the needs of the training programme may limit to a greater degree the extent to which supersonic flight by the Services can be similarly restricted.

My right hon. Friends and I are aware of the disturbance and anxiety which sonic bangs can cause, and we do not regard the revised regulations as final; but they should secure that the disturbance to the public is materially reduced.

All claims for damage caused by sonic bangs are carefully investigated—normally by members of the Air Ministry staff—and compensation is paid by the Department concerned on the same basis as if the Crown were legally liable.

Mr. C. I. Orr-Ewing

Will my hon. Friend assure us that there will not be undue difficulty in getting permission to fly supersonically at low levels for exercise purposes? Some of us feel that potential enemies may not approach this country from very high level but from very low, and that unless realistic exercises are undertaken they will make nonsense of our defence forces.

Mr. Maudling

That is really a question for my right hon. Friend the Secretary of State for Air.

Mr. Wigg

Is the Minister aware that his statement will give general satisfaction, provided that it is applied rigidly and that we do not get any more cases of aircraft companies organising supersonic bangs in order to refute irresponsible statements in Sunday newspapers?

Mr. Maudling

I am not prepared to accept the implication of that supplementary question.