The Hawker Hunter T.Mark 7 was a two-seat trainer version of the Hunter powered by the small Rolls-Royce Avon used on the F.1 and F.4 rather than the large Avon of the F.6 and later models.
Work on a two-seat trainer began as a private venture in 1953. At this stage Hawkers considered both tandem and side-by-side versions of the aircraft. The tandem version would have been the easiest to produce, and would have been fastest, but the side-by-side version was favoured by the instructors and staff at the Central Flying School and the Day Fighter Leaders' School as it made it easier to demonstrate controls, sight weapons and teach instrument flying. The side-by-side layout was thus adopted for the T.7, and in 1954 Specification T.157D was issued. Hawkers were asked to built a single prototype.
The first version of the design used a double-bubble canopy, with a slight dip between the two crew positions, and similar canopy-to-fuselage fairing as on the fighter aircraft. By the time the first prototype was under construction the double-bubble had been replaced by a smooth single piece canopy. The first prototype, KJ615 (Hawker designation P.1101), was powered by the smaller Avon Mk.113 R.A.21 engine, and was initially armed with two 30mm cannon. This was later changed to a single gun and the port Aden cannon was removed.
KJ615 made its maiden flight on 8 July 1955. It was immediately clear that the new cockpit was causing severe airflow problems. At about Mach 0.84 airflow instability began to build, and at Mach 0.88 the aircraft began to snake and pitch about. Hawkers was forced to produce a new fairing to link the cockpit to the rear fuselage. On the single-seat Hunter this fairing is short and narrow, and barely reaches the wing roots. After more than twenty different designs were tested the eventual version for the T.7 was a much large 'hump-backed' design that stretched back more than half-way along the fuselage. With this in place the snaking and pitching problems were solved.
By the middle of 1946 the problem with fairing had been solved. Hawkers received both a production order and permission to build a second prototype, XJ627, powered by the larger 200 Series Avon engine that was used in the F.Mark 6 and all later RAF Hunters. This aircraft made its successful maiden flight on 17 November 1956, but the large engined trainer was not ordered into production for the RAF. Instead it would sell on the export market, starting with the T.Mark 66. The RAF would only acquire a single large-engined two-seater, the Hunter Mark 12.
The original Ministry of Supply contract was for 55 aircraft, all with the small 100 Series Avon engine, to be produced by Hawkers at Blackpool. The 1957 defence cut-backs meant that there was now spare capacity at Hawker's Kingston factory, and production was switched to that plant. Forty-five T.7s were produced for the RAF at Kingston, with the first one making its maiden flight on 11 October 1957. The remaining ten aircraft were transferred to the Admiralty, where they became the first T.Mark 8s. Another order for ten new aircraft was placed at some point, but was then cancelled and the aircraft used to fill half of a Dutch order for twenty trainers. This probably came at the same time as an order to convert six existing F.4s to the T.7 standard, work that took place in the same years as the Dutch production.
The first production T.7 made its maiden flight on 11 October 1957. In the following year the T.7 was issued to 229 OCU at Chivenor, and then over the next few years the type was issued in small numbers to most operation Hunter units, both in the UK and with 2nd TAF in Germany. The T.7 was also issued to 4 FTS at Valley, Anglesey in 1967 where it was used for advanced pilot tuition. The type remained in general use until the introduction of the BAe Hawk. A small number were then given modified cockpits with Buccaneer controls and used for Buccaneer training at Lossiemouth.
After the introduction of TACAN (Tactical Air Navigation) equipment a small number of T.7s were modified to carry this equipment, with the designation T.Mark 7A.
Engine: Rolls Royce Avon Mk.122 (R.A.21) turbojet
Power: 7,550lb thrust
Wing span: 33ft 8in
Length: 48ft 10.5in
Height: 13ft 2in
Empty Weight: 13,360lb
Maximum Weight: 17,200lb
Max Speed: 694mph at sea level; Mach 0.92 at 36,000ft;
Climb rate: 12.5 minutes to 45,000 feet
Service Ceiling: 47,000ft
Range: 1,900 miles with tanks
Armament: One 30mm Aden cannon
Bomb-load: Capable of carrying stores on four under-wing pylons