Built during 1939-41 as a grass airfield satellite to RAF Tangmere, Merston initially had no fixed runways, 17 hardstandings, 12 double pens and six blister hangars. Occupied by RAF fighter squadrons from May 1941 to August 1942, it had been allocated to the Eighth Air Force in June 1942 as a satellite to RAF Westhampnett. It eventually became home to the 307th Fighter Squadron of the 31st Fighter Group, equipped with Spitfire Vs, during August to October 1942. The station then closed for redevelopment with two Sommerfeld Track runways and other improvements. Re-opened in May 1943 as an RAF fighter station, it was re-allocated to the Eighth Air Force in July 1943, and transferred to the Ninth Air Force in October 1943, but was never again used by American squadrons. The airfield closed in August 1944 when the process began of returning the site to agriculture. It was used by briefly by Air Disarmament Units of SHAEF during March to May 1945, and then by the Royal Navy for storage of war surplus equipment until finally closed in November 1945.