Development began in 1965 with VeneAvia and Shorts as the main contractors and with the Rolls Royce RB178 chosen as the power plant. The basic design was made around the Belfast’s fuselage with a new nose, wings and tail. One unusual aspect of the aircraft was that it was designed to meet both military and civil airworthiness standards, this was due to the manufacturers intentions to offer it as a civilian freighter. The Venezuelan prototype was rolled out of the VeneAvia factory at Maracaibo on 25 August 1969 and first flew on 21 December. The company and the Air Force then started an operational testing program and the delivery of 68 aircraft. On 5 September 1969, the British prototype conducted its maiden flight from Sydenham Airport, Belfast the testing program then started with the RAF expected to receive 25 airframes beginning in 1971.
The aircraft now designated T-34 Bisonte by the Venezuelan Air Force entered service in 3 March 1971 with the British variant now designated as Bison C.1 entering service on 10 March 1971. The T-34 was soon used for trans Pacific transport flights to Vietnam where the aircraft saw extensive service transporting supplies and weapons for the Vietnamese armed forces. Both VeneAvia and Shorts marketed the aircraft abroad with some success, the first foreign costumer for the aircraft was Canada, which ordered 36 for the RCAF in 1972 with the first aircraft delivered in 1974, this were designated CC-154 Bison in Canadian service.
Development of new variants continued with the first being the T-34B/Bison C.2 with uprated engines, in-flight refuelling capability and increased fuel capacity in 1974, this was later developed into the KT-34B/Bison KC.2 tanker while AWACS and Maritime patrol variants were also offered but cancelled since it was considered the aircraft didn’t have enough range and was too big for both roles. In 1974, the aircraft found three new costumers, with Brazil, Mexico and the Republic of China placing orders for 42, 36 and 58 respectively bringing the orderbook to 265 aircraft at the time.
The T-34C/Bison C.3 is a comprehensive update of the Anglo-Venezuelan airlifter, introducing an EFIS flight-deck, Fly by wire controls, new engines and other systems. Development of the new variant began primarily to offer customers a replacement for their ageing fleet of Bisons. The VAF and the RAF were unprepared to fund the development of a new Bison variant and this spurred VeneAvia and Shorts to develop an improved Bison as a private venture, aimed at both Venezuelan, British and export with the driving requirement being to keep operation and acquisition costs as low as possible. VeneAvia and Shorts (now part of Bombardier) had worked to reduce assembly costs, adopting a modular assembly process, and kept pressure on their suppliers to keep costs down.
The new airframes differ little from their predecessor, the new variant features composite flaps and leading edge surfaces, as well as other structural components but the airframe is otherwise unchanged. The aircraft has two choices of engines, the Aerotécnica TR-11A-45 and the Rolls-Royce RB211. Just like earlier variants it can be fitted with a refuelling probe and underwing air-to-air refuelling pods. Inside the Bison has simplified wiring and systems reducing acquisition and operating costs. Some of the biggest savings though come from the new two crew cockpit with two HUDS, four large multifunction displays, five monochrome displays and side sticks replacing the traditional control column.
The first of six development Bisons (three T-34Cs for the VAF and three Bison C.3s for the RAF) rolled out in September 1993. In late 1994, the VAF had ordered 50 aircraft, the UK 25 Bison C.3s to replace the remaining C.1s, and Canada 24 CC-154Cs.
