|During the mid-1960s the RAF increased its emphasis on high-altitude training, and this showed up a weakness in the Jet Provost T.4. The aircraft were not pressurised placing severe physical strain on the aircrews.|
In 1964 Hunting-Percival, then a part of BAC (British Aircraft Corporation) responded to this problem and began work on a new pressurised version as a private venture. The company utilised the last two T.4s of the large RAF order placed previously (XS230 and XS231) and began to convert these into the prototypes for the new version, the Jet Provost Mk.5.
Following three years of work, which began at Luton but was moved to BAC's Warton factory in 1966, XS230 undertook its first flight on 28 February 1967. Powered by the Rolls Royce Viper 201, the same as used in the T.4, XS230 looked cosmetically different from its T.4 sisters.
The cockpit hood was re-designed and the front fuselage took on a more bulbous shape to accommodate the necessary pressurised cockpit.
The canopy slid upwards instead of back, the wings were strengthened to carry bigger tip tanks, and a new improved cockpit avionics package was installed. XS231 was built to identical standards, but was fitted with a more powerful Viper engine, capable of 3000lbs of thrust, and was placed on the UK civil register as G-ATAJ.
Both the aircraft were sent to Boscombe Down for tests and evaluation by the MoD.
The RAF saw the finished design in action at Boscombe and after deliberation made a firm order for yet more Jet Provosts, this time 110 T.5s.
The first example off the production line was XW287 and it was the first T.5 to enter RAF service, being handed over to the Central Flying School based at RAF Little Rissington on 3 September 1969. Further examples followed throughout 1970 with the Royal Air Force College (RAFC) at Cranwell, and RAF Linton-on-Ouse unit 1FTS joining the Central Flying School as initial users of the type.
Further units adopted the Mk.5 as they came onto RAF charge from the Warton factory; 3FTS based at Leeming, 6FTS based at Acklington and 7FTS at Church Fenton all received JP 5s.
The Jet Provost T.5A also equipped several RAF aerobatics teams such as the Poachers from RAF Cranwell and "The Swords" based at RAF Leeming with 3FTS.
At first it was forecast that the T.5 would take the place of the T.4 on certain roles such as high altitude training. Unfortunately the majority of T.4s had to be taken out of RAF service much earlier than anticipated so the T.5 had to take on more responsibilities.
As a result, the RAF decided to update its fleet of Jet Provosts with new avionics suites, spin strakes, and roughened leading wing
edges in 1973.
The full capabilities of carrying fully-laden tip-tanks was partially sacrificed in the upgraded version - the Jet Provost T.5A.
Originally BAC updated 94 T.5s of the 110 delivered between 1973 and 1976, and these went on to serve the RAF with distinction for the next 15 years.
The last version of the Jet Provost was the unofficial 'T.5B', a small number was converted to be used as navigational trainers complete with refitted tip-tanks, and these served with 6FTS based at RAF Finningley alongside Jetstream T.1s and Dominie T.1s.
In 1988 the RAF made a final decision on the Jet Provost's replacement, the Shorts Tucano T.1, a turboprop aircraft.
This initiated the winding down of the RAF Jet Provost fleet, but it took some time before the last example was finally retired from the training syllabus. 1991 saw 7FTS withdraw the JP from their training fleet, following in the footsteps of the Royal Air Force College and the Central Flying School, who had an operational Tucano fleet. 6FTS and 1FTS were the last to retire their Jet Provosts.
On 20th September 1993 the curtain was finally brought down on the Jet Provost's RAF career.
It spanned some 38 years, saw 500 examples being produced and helped earn the flying wings of hundreds of trainee pilots.
Five T.55's, export versions of the T.5, were also built and sold to Oman, and the type also enjoyed success in the overseas market with Sri Lanka, Kuwait, Iraq and Venezuela Air Forces.