The CHAIRMAN, in introducing the Author, expressed great pleasure in welcoming Mr MacMahon to this, the first lecture of the eleventh series of Annual Lectures on the helicopter situation He said that Mr MacMahon was educated at Twickenham Technical Institute During the war, he was with the Admiralty Research Laboratory, working on electromc equipment for anti-submarine warfare development After that, he was engaged on electronic developments with one or two firms and subsequently with the De Havilland Propellor Company as a development engineer engaged mainly on research and development of flight test equipment for high speed aircraft

Considerable work has been done on wind tunnel testing of helicopter and autogyro rotors and of specific helicopter fuselages but there is no available information on the wind tunnel development of a complete design prior to construction of a prototype helicopter With interest in the stability and control of helicopters and to assist the development of a specific design the wind tunnel development was undertaken by the Aeronautical Research Laboratories