at RAF Brawdy in Wales to train Forward Air Controllers. The later T4 was fitted with the more powerful Viper A.S.V. 11 of 2,500 lbs static thrust and first flew on 15 July 1960. It quickly entered service with the units listed above. The T5 variant was fitted with the Viper 201 and cockpit pressurisation. These developments encouraged the RAF to utilise the Jet Provost in a number of different roles besides basic training. With a top speed of 440 mph, excellent maneuverability, mechanical reliability and low operating costs, the Jet Provost was utilized as an aerobatic aircraft, air warfare and tactical weapons training as well as advanced training. The first T5 made its maiden flight on 28 February 1967 and deliveries from BACs Warton factory commenced on 3 September 1969. Operators of the T5 included the RAFs Central Flying School and No. 1, No. 3 and No. 6 Flying Training Schools. Besides service with the RAF, the Jet Provost found success in export markets. A single Jet Provost T2 was exported to Australia and was operated by the Royal Australian Air Force (RAAF) to evaluate the type for the purpose of providing 'all-through' jet-based training. Following a six-month evaluation period, the RAAF ultimately decided to retain the de Havilland Vampire to fulfill its requirements for a jet-powered trainer, and later replaced its Vampires with the Italian-built Aermacchi MB-326 during the late 1960s instead. The sole aircraft itself was retained, being presented to the Sydney Technical College for use as an instructional airframe, and was later preserved. Ceylon ordered 12 Jet Provost T51, these went into operational service in early 1960, one crashed in February 1960 following a flame out. The Provost were meant for pilot conversions for jets and intended as a stepping stone to introduce jet fighters to the Royal Ceylon Air Force (RCyAF). However these plans were scrapped due to defense cuts following the attempted coup in 1962 and by the late 1960s the remaining Provosts were mothballed. With the outbreak of the 1971 JVP insurrection in April 1971, the RCyAF took out its mothballed Provosts and started a crash program to bring these to operational readiness in three days. These Provost carried out ground attack sorties on insurgent targets, vectored in by helicopters that used smoke bombs to mark targets for Provosts. One Provost crashed returning from a sortie and its pilot killed. Nigeria acquired two