Mr. ROSTRON DUCKWORTHasked the Under-Secretary of State for Air whether, in view of the fatal accidents to aviators through colliding with hillsides, especially on the Continent, he can state what progress is being made with world research into inventions to show the altitude of machines in relation to the nearest high surface of land?
§ Sir P. SASSOONNotwithstanding research in various countries it is doubtful whether any reliable instrument of this nature exists which is suitable for general adoption in aeroplanes, other than the existing altimeter based on air pressure: the Air Ministry is keeping in close touch with developments in other countries and an echo-sounding device which shows some promise is at present being investigated.