Station design

It was constructed with four hard runways and associated facilities. The control tower was built on top of the operations block. The main technical area was situated to the south west of the site, with other hangars and dispersal areas spread around the airfield.^[4] There were twenty-eight hangars with twenty-one used for the FAA squadrons and seven for storage. The site also had one Aircraft Repair Shed (ARS),^[5] which was a Bellman hangar measuring 185 feet (56 m) x 105 feet (32 m) The others we made up of sixteen Mains hangars, each measuring 60 feet (18 m) x 70 feet (21 m) and twelve Skeabrae hangars which measured 60 feet (18 m) x 50 feet (15 m).

Accommodation consisted living quarters at Skogar Camp with additional quarters at Linklater and West Quoys, with capacity for 173 Officers and 7 W.R.N.S. Officers with 965 Chiefs, P.O.s and ratings and 35 W.R.N.S. Chiefs, P.O.s and ratings.^[3]

Fleet Requirements Unit

One of the roles of the airbase was to provide an airfield to a Fleet Requirements Unit, which was tasked with operational training for the Home Fleet, which was based in Scapa Flow.^[5]

In July 1942, 771 Naval Air Squadron relocated to RNAS Twatt, from RNAS Hatston (HMS Sparrowhawk), which was also located on Orkney. It brought with it a variety of aircraft including Fairey Swordfish, a biplane torpedo bomber, Hawker Henley, a two-seat target tug, Blackburn Skua, an aircraft carrier-based dive bomber/fighter aircraft, Blackburn Roc, an aircraft carrier-based turret fighter, Bristol Blenheim, a twin-engine light bomber, Gloster Sea Gladiator, a biplane fighter, Vought Chesapeake an American aircraft carrier-based dive bomber, and Martin Maryland, an American light bomber (the squadron and the latter aircraft were directly responsible for starting the chain of events that led to the sinking of the German battleship Bismarck whilst stationed at HMS Sparrowhawk, just prior to moving to HMS Tern).^[6]

In the later part of 1942 Boulton Paul Defiant target tug aircraft began to arrive. The converted turret interceptor aircraft supplemented the Blackburn Skua and Blackburn Roc target tugs. From 1943 these three aircraft types were replaced with Miles Martinet which was specifically designed as a target tug aircraft. Douglas Boston medium bomber variants were acquired to operate alongside the twin-engined Bristol Blenheim and Martin Maryland light bombers. All these types exercised the ships of the Home Fleets' and shore-based, anti-aircraft guns and also provide targets for radar practice and calibration. Hawker Hurricane single seat fighter aircraft, provided higher speed targets and these aircraft replaced the Vought Chesapeake dive bombers.^[6]

‘A’ Flight of 700 NAS, which was equipped with Supermarine Walrus, a single-engine amphibious biplane, moved to HMS Sparrowhawk and became ‘B’ Flight of 771 NAS, on 24 March 1944. The flight swapped its Supermarine Walrus for Supermarine Sea Otter, a biplane amphibious aircraft. In the following August the flight became 721 Naval Air Squadron. In 1945 the Hawker Hurricane aircraft were replaced with the faster Vought Corsair, an American fighter aircraft.^[6] In February of that year the squadron received its first helicopter with the arrival of Hoverfly I, a two seat helicopter.^[5] The squadron operated a detachment at RAF Warmwell, in Dorset, England, from 14 June to 1 August 1945. 771 NAS left RNAS Twatt on 25 July 1945, moving south along with the Home Fleet following VE Day, to RNAS Zeals (HMS Hummingbird), in Wiltshire, England.^[6]

Catapult training

700 Naval Air Squadron formed at RNAS Hatston (HMS Sparrowhawk) on 21 January 1940. It moved its HQ the short distance across Mainland, Orkney, to RNAS Twatt (HMS Tern) during June 1942 and at that point the squadron was equipped with sixty-three Supermarine Walrus amphibious biplanes.^[7]

At the time the squadron moved its HQ, known as ‘A’ Flight, to RNAS Twatt it provided a ten week training course for new catapult Flights. The final two weeks of the course were spent attached to ‘A’ Flight at RNAS Twatt for final training, before joining their allocated ship.^[5] The training was broken down into an initial three weeks of aerodrome flying, consisting circuits and landings, dive-bombing, photography and anti-submarine warfare, at RNAS Donibristle (HMS Merlin), in Fife. A second three week block was spent at RNAS Dundee (HMS Condor II), a seaplane base / repair depot, in Dundee, where the focus was on water operations, which included night landings. Week seven was a catapult course aboard HMS Pegasus, a Royal Navy aircraft carrier/seaplane carrier, in the Irish Sea. Week eight was then a return to RNAS Donibristle (HMS Merlin).^[7]

As radar was being introduced to Royal Navy capital ships, and with the emergence of the Merchant Aircraft Carrier (MAC ship) and the escort carrier the need for catapult aircraft greatly reduced and by July 1943 the squadron was down to twenty aircraft.^[7] 700 NAS disbanded the following year on 24 March 1944,^[5] with the remains of 'A' Flight becoming 771 NAS ‘B' Flight at HMS Sparrowhawk.^[7]

Torpedo Bomber Reconnaissance Squadrons

A number of Fleet Air Arm torpedo bomber squadrons spent time at RNAS Twatt either working up for deployment, returning from deployment, or passing through between airbases.

Fighter Squadrons

A number of Fleet Air Arm fighter squadrons passed through HMS Tern either working for deployment, or returning from operations, throughout the Second World War.

Post VE day

With Germany's unconditional surrender of its armed forces on Tuesday, 8 May 1945 and the disbandment of the catapult training unit, 700 NAS, the previous year, the airbase saw a lot less activity. A couple of FAA squadrons passed through shortly after VE Day and the Fleet Requirements Unit remained at RNAS Twatt until July 1945.