HMS Tern – or Royal Naval Air Station Twatt – operated as a vital part of the Royal Navy’s presence in Orkney while Scapa Flow was the base for the Home Fleet in WWII. It was one of four airfields set up in Orkney during WWII.
Although the aircraft based at Tern formed part of the defences of Orkney, the site’s main role was to provide training facilities for the Navy. Also, when the Fleet’s aircraft carriers were in harbour, their aircraft would fly ashore rather than stay on board, and the facilities at Tern and other airfields in Orkney were expanded to accommodate the extra squadrons.
The airfield started operating in 1941. Many different squadrons were based there, flying many different types of ‘plane – Gladiator, Swordfish, Roc, Skua, Seafire, Chesapeake and more. After WWII the station was ‘mothballed’, but was in the care of the Royal Navy and maintained as a usable station until sold off in 1957.
Birsay Heritage Trust with the help of Aviation Research Group Orkney & Shetland (ARGOS) have been working to clear the site and open up more of the remaining buildings for visitors. The Control Tower, Cinema and Fire Station are the main focus at the moment, and all three feature on guided tours.