During the Second World War, the construction of airfields boomed in Northern Ireland. Throughout the conflict, a total of 29 sites served as airfields for the Royal Air Force, Royal Navy, and United States Army Air Force. The size of sites and their functions varied across Ulster at different periods of the conflict. Some sites served only as satellite landing grounds while others were operational aerodromes. One airfield never made it past the construction stage, and some still remain in use today.
Following the outbreak of war in 1939, authorities earmarked Northern Ireland as a good site for aviation training. The landscape offered large areas of flat land, and crews would be far from the frontlines in Europe. Around the north coast, airfields offered easy access to the north Atlantic, aiding the search for U-Boats and the covering of convoys.
The Coastal Command station at Aghanloo Airfield near Limavady, Co. Londonderry operated as R.A.F. Limavady. It was the first of four airfields in the area.
Aldergrove Airfield, now the home of Belfast International Airport, saw use as a base for several squadrons of the Royal Air Force during the Second World War.
Langford Lodge Airfield on the east coast of Lough Neagh near Crumlin operated as a base for both the R.A.F. and the U.S.A.A.F. during the Second World War.
Maghaberry Airfield in Co. Antrim operated as an airfield for both the Royal Air Force and the United States Army Air Force during the Second World War.
Nutts Corner Airfield in Co. Antrim became a Royal Air Force base during the Second World War. It also operated as a transport hub for American military planes.
During the Second World War, the newly-built airfield at Sydenham accommodated squadrons from both the Royal Air Force and the Fleet Air Arm of the Royal Navy.