Installation, Leith Hill Mr. Harris asked the Under-Secretary of State for Air whether the installations erected by the R.A.F. on Leith Hill, Surrey, are temporary or permanent; and if the former when will they be removed. Mr. Strachey The installation at Leith Hill forms a provisional and experimental part of a radar system that is designed to enable transport aircraft to use airfields near London with the maximum of safety in all weather conditions. Its introduction is one of the measures which have followed the statement made to the House by the Secretary of State for Air on 10th April that the navigational aids given to Transport Command would be accorded an increasing priority. Alternative sites are being sought for a possible permanent installation. Before final decisions are made we shall arrange for and welcome full consultation with the public amenity interests affected.