The Hawker Sea Fury was to become the Fleet Air Arm's last piston-engined fighter. Development had started in 1943, for the Royal Air Force (RAF), intended as a successor of their highly successful Typhoon and Tempest fighters.

During April 1944 production contracts were placed for 200 Fury I aircraft for the RAF and an equal number of Sea Fury aircraft for the Fleet Air Arm, of which 100 were to be built by Boulton Paul Aircraft Ltd. A few months later, with the Allied armies gaining a strong foothold in France after the D-Day landings and with the end of the World War II in Europe in sight, the production order for the RAF Fury was cancelled. The Royal Navy however considered the aircraft a suitable replacement for its ageing carrier borne fighters and pressed for continuation of the development of the Sea Fury.

At a relatively late stadium a two-seat training version of the Sea Fury entered production. When negotiating the purchase of Furies for their Air Force, the Iraqi government had enquired on the feasibility of a two-seat trainer/conversion aircraft to assist transition to the high performance Hawker fighter. The British Admiralty also realised this potential and an order for one prototype to Specification N.19/47 was ordered on 23 June 1948. Some time earlier, the prototype originally ordered by the Iraqi Government (with serial 264) was diverted to the Royal Navy. The aircraft, VX818, was built at Kingston and was completed at Langley, making her first flight there on 15 January 1948. Handling trials followed by C Squadron, Aeroplane&Armament Experimental Establishment (A&AEE) at Boscombe Down in March 1948. During one of these flights the rear cockpit canopy collapsed, as it turned out due to excessive aerodynamic forces. As a remedy a perspex 'tunnel' connecting the two cockpits was added. This feature became standard on all Fleet Air Arm T.20s. The two-seat T.61s for the Pakistan Air Force and the two Fury IDT two-seat aircraft for the Iraqi Air Force still featured the earlier two-cockpit lay out. In January 1952 VX818 was delivered to the Empire Test Pilots School (ETPS) at Boscombe. An engine failure on 22 June 1964 resulted in a forced landing some 11 miles from her base. On landing VX818 desintegrated.

Dimensions of the T.20 equalled those of the FB.11. The addition of an extra cockpit for the instructor necessitated the relocation of equipment. Therefore two of the 20mm cannon were dispensed with, to allow the installation of oygen bottles (in the port wing) and additional avionics in the starboard wing. Another feature of the (FAA) T.20 was the periscopic sight mounted over the 'tunnel' between the two cockpits. Often referred to as the 'tripod', the sight was actually mounted on four legs and allowed the instructor to monitor his pupils main flight instruments and gun sight. As on the FB.11, the T.20 could carry two 90-Imp Gallon (409 litres) fuel tanks as well as the armament of the fighter-bomber.
The T.20 also had provision to carry 'Rato-bottles' for rocket-assisted take-off, but these were never seen being used. Not intented for carrier operations, the T.20 had no tail hook. Contrary to the T.20 prototype, all production T.20s featured a fixed tail wheel. In more recent years however, some warbird operators opted their T.20 to have the tail wheel retractable, as in the TFC's example WG655. This machine had the characteristic 'tripod' removed. Unfortunately WG655 was lost in an accident on 4 August 2020, when pilot Eskil Amdal had to make a forced landing near Harston in Cambridgeshire. He and 'navigator' Dave Unwin escaped with injuries.

Deliveries of the T.20 to the Fleet Air Arm began in February 1950.


Sea Fury T.20 production and serials
The manufacture of the T.20 was covered by 5 contract blocks and totalled 60 production aircraft and one prototype:

VX818 (1 a/c), the T.20 prototype.
VX280-292, VX297-310 (27 a/c).
VZ345-355, VZ363-372 (21 a/c).
WE820-826 (7 a/c).
WG652-656 (5 a/c).