Required primarily as an RAF and USAAF transport staging post, St Mawgan was built during

1942-43 as an enlargement of the inadequate RAF Trebelzue airfield. The two existing runways were retained as dispersals and three new, longer runways were laid down, together with a new perimeter track and hardstandings. The main runway was extended in early 1944. Limited RAF operations from Trebelzue continued while St Mawgan was being constructed, and the first Americans arrived in June 1943 before the first of the new runways was opened in July 1943. St Mawgan became home in June 1943 to the 491st Base and Air Base Squadron of USAAF Air Transport Command, working alongside No. 2 Overseas Aircraft Despatch Unit of the RAF. The station quickly became one of the busiest airfields in the UK for transit aircraft and remained so throughout the Second World War. Movements from and to the USA were intensive during 1943-45, as were movements onward to North Africa and other wartime theatres of operation, including ultimately the Far East. The station was also occupied briefly by two USAAF Meteorology Flights during November 1943, while BOAC operated some scheduled services via St Mawgan from November 1943 to November 1944. The total movements for 1944 were a remarkable 16,110. On 17 February 1944 alone, 169 American aircraft arrived from the USA. During the winter of 1944-45, the station was also used by the 8th Air Force and the RAF for large-scale bomber diversions, and it became in June 1945 a jumping-off point for USAAF aircraft returning home, after the end of the war in Europe. The Americans handed over their facilities at St Mawgan to the RAF in August 1945. The station closed in 1947 but re-opened in 1951. The airfield part of the site was sold in 2008 for operation as Newquay Cornwall Airport, while the rest of the station continues today primarily as home to the Defence Survive, Evade, Resist, Extract (SERE) School, known locally as the DSTO, and to Defence Training Estates (DTE).