Air-Sea Warfare Development Unit RAF

On the 22 October 1940 the Coastal Command Tactical Development Unit was formed at RAF Carew Cheriton. It was equipped with Armstrong Whitworth Whitley V, a British medium bomber aircraft, Lockheed Hudson I, an American light bomber and coastal reconnaissance aircraft, Bristol Beaufort I, a British twin-engined torpedo bomber and Vickers Wellington IA, a British twin-engined, long-range medium bomber.[2]

The unit was short lived with this identity and after two months it lost the Tactical from the title. On the 30 December 1940, the unit disbanded but immediately reformed, redesignating as the Coastal Command Development Unit.[3]

Bristol Beaufort Mark I, N1174, of the Coastal Command Development Unit based at Carew Cheriton, fitted with ASV (air-to-surface vessel) Mark II radar, while undergoing trials. The transmitter antenna is the black object mounted under the nose; the receiver is the much larger black antenna fitted under the wing.

For the initial radars to be effective, operational techniques and skilled operatives were required.[4] The Coastal Command Development Unit undertook service trials of all radar equipment such as ASV (air-to-surface vessel) radar for RAF Coastal Command operations. Although it had its own aircraft, it also used flying boats from RAF Pembroke Dock,[5] a Short Sunderland, a British flying boat patrol bomber, was used fitted with ASV Mk1 for the first trial, and it was soon realised the value of the CCDU, therefore, its role changed to cover both service and tactical trials of all RAF Coastal Command aircraft and equipment.[4]

In January 1941 two Vickers Wellington were used to investgate into the use of bomb and depth charges for attacks on submarines and surface vessels by night with the aid of parachute lights, and later with Leigh Lights. The unit operated out of RAF Carew Chriton for around twelve months before moving to RAF Ballykelly in December 1941.[5] Around six months later it then moved to RAF Tain, during June 1942,[6] and remained there for almost a year.[7]

In April 1943 the Unit took over RAF Dale[8] relocating from RAF Tain.[9] In September 1943, as part of the swap between the Royal Air Force and Royal Navy with Dale and Angle airfields, the Unit moved to RAF Angle[10] One of the key tests performed while at RAF Angle was to measure audibility of aircraft from submarines on the surface.[5] Utilising Leigh Light (L/L) and radar search, it carried out trials to see how close to a submarine the different aircraft types the unit used could get, before they were audibly detected.[11]

On 14 January 1945 the Air-Sea Warfare Development Unit formed at RAF Thorney Island by redesignating the Coastal Command Development Unit.[1] The role of the ASDWU was to increase efficiency in maritime operations by carrying out trials on the latest equipment. It also contributed to the development through collaboration with other research and development establishments.[12] At the end of 1944 a similar unit was set up in Ceylon (Sri Lanka) to conduct trials of equipment supplied to South East Asia Command, lasting around twelve months.[1]

The unit moved to RAF Ballykelly in May 1948 and along with the trials work it also provided aircrew training for operational squadrons. It moved to RAF St Mawgan during May 1951, and remained there for the next seven years, before returning to RAF Ballykelly in September 1958.[13] While at RAF St Mawgan it operated the Bristol Sycamore helicopter, between 1952 and 1955, for various trials.[14]

The Air Sea War Development Unit disbanded on 1 April 1970, at RAF Ballykelly,[1] when control of all trials work for the Hawker Siddeley Nimrod maritime patrol aircraft fleet was assumed by the Central Trials and Tactical Organisation.[12]