In 1941, RAF Fighter Command planned to use the airfield for an experimental unit, and after requisitioning land from several adjacent farms, contracted George Wimpey and Company to begin work on 11 June 1941. However, its intended use soon changed into being a satellite airfield for the fighter squadrons based at RAF Colerne. Originally, the new airfield's name was to be RAF Broadfield Down. The airfield used a standard-issue three-runway layout resembling an A shape. The main, east-west runway was long, with a designated alignment of 28/10, and the others were aligned 21/03 and aligned 34/16. The first aircraft to land was a Luftwaffe Ju 88 at 06.20 on 24 July 1941. Returning from a raid, its crew had been deceived by the RAF electronic countermeasures radio beacon at Lympsham, which was re-radiating the signal from a Luftwaffe homing beacon at Brest, France.