Air Fighting Development Unit RAF

The Air Fighting Development Unit (AFDU) was an air technical intelligence part of the Royal Air Force which developed operational tactics and tested captured enemy aircraft. It was based at Royal Air Force Stations at Northolt, Duxford and Wittering.
The Air Fighting Development Unit was under the control of RAF Fighter Command and the Air Ministry, and performed comparative trials and developed and promulgated tactics effective against the enemy. Also sharing Wittering with the AFDU was the Naval Air Fighting Development Unit.
These units were also tasked to carry out a variety of tests and evaluations on a wide range of fighter aircraft, aircraft modifications and new equipment prior to entering Allied service.
It was formed as the Air Fighting Development Establishment at Northolt on 20 October 1934; being re-designated as the Air Fighting Development Unit in July 1940.
The units were absorbed into the Central Fighter Establishment and moved to RAF Tangmere in 1945.
Operation Banquet.
The Air Fighting Development Unit, under Operation Banquet anti-invasion plans, was allocated the title No. 550 Squadron RAF.
Reconstitution as Air Fighting Development Squadron.
The AFDU was reconstituted in the 1950s at RAF Tangmere as the Air Fighting Development Squadron (AFDS), subsequently relocating to RAF Coltishall where it operated the BAC Lightning jet fighter in its P.1B, F.1 and F.1A variants. The AFDS later relocated to RAF Binbrook in October 1962, operating the F.2 and T.4 variants until the squadron was absorbed by the Central Fighter Establishment (CFE).