The limitation of the purpose of the Victory Bomber to only a single bomb and mission did not endear it to the Air Ministry, who required more flexibility of their aircraft. In mid 1940, a principle had been established that the manufacturing of only five types of aircraft should be pursued – two of these being fighter aircraft and three being bombers; Wallis' vision for a six-engine bomber equipped for only a specialised bomb conflicted with this concept. However, Lord Beaverbrook committed support for the project, co-operation from both the Ministry of Aircraft Production and the Road Research Laboratory would be forthcoming to aid Wallis in developing his plans. In August 1940, the Aeronautical Research Committee permitted the use of a wind tunnel at the National Physical Laboratory in Teddington to perform tests to develop the penetration bomb.