RAF Longtown

Military consolidation and economic reasons. The UK Ministry of Defence closed the site as part of its 'A Better Defence Estate' strategy. This initiative aimed to rationalize its extensive property portfolio, reduce running costs, and centralize munitions storage and distribution operations at a more modern facility, DM Kineton in Warwickshire, making the Longtown depot redundant.

The site is closed and no longer owned or operated by the Ministry of Defence. It has been sold and is now a large brownfield site slated for major redevelopment. In 2023, it was announced that the site would be transformed into the 'Longtown Borderland Low Carbon Fuel Hub'. Plans focus on creating a large-scale logistics and industrial park centered on the production and distribution of low-carbon fuels, leveraging its strategic location near the M6 motorway and the UK-Scotland border.

RAF Longtown was never a conventional airport or flying station with squadrons. It was established in 1939-1940 as No. 14 Maintenance Unit (MU), a vast and strategically vital chemical weapons and ammunition depot. Its primary role during World War II was the storage, maintenance, and distribution of armaments, most notably holding the UK's main stockpile of mustard gas. The site was designed with widely dispersed bunkers and storage sheds connected by an extensive internal railway system to minimize the impact of an enemy air raid. After WWII, it continued as a major conventional ammunition depot for the RAF and later evolved into Defence Munitions (DM) Longtown, serving all three branches of the UK armed forces. The ICAO code GB-0167 likely refers to a small, private airstrip on the massive site for light communication aircraft or helicopters, rather than a fully operational airport.

There are zero plans or prospects for reopening the site as an airport or airfield. Its historical function was ground-based storage and logistics, not significant aviation operations, and its infrastructure is not suitable for a modern airport. All future development plans are firmly focused on industrial, commercial, and logistics use, specifically in the renewable energy and low-carbon fuel sectors.