Royal Air Force and anti-aircraft chiefs leading "Exercise Bulldog" at Bomber Command Headquarters at High Wyecombe, Buckinghamshire, England. L-R: Air Marshal Sir Aubrey Ellwood (Bomber Command); Air Marshal Sir Basil Embry (Fighter Command) ; General Sir G. Ivor Thomas (Anti-Aircraft Command) ; Major General Leon W. Johnson (Commanding General, Third Air Division, United States Air Force) 22 September 1949