The T-34 was the brainchild of Walter Beech, who developed it as the Beechcraft Model 45 private venture at a time when there was no defense budget for a new trainer model. Beech hoped to sell it as an economical alternative to the North American T-6/NJ Texan, then in use by all services of the U.S. military.
Three initial design concepts were developed for the Model 45, including one with the Bonanza's signature V-tail, but the final design that emerged in 1948 incorporated conventional tail control surfaces for the benefit of the more conservative military (featuring a relatively large unswept vertical fin that would find its way onto the Travel Air twin-engine civil aircraft almost ten years later). The Bonanza's fuselage with four-passenger cabin was replaced with a narrower fuselage incorporating a two-seater tandem cockpit and bubble canopy, which provided greater visibility for the trainee pilot and flight instructor. Structurally the Model 45 was much stronger than the Bonanza, being designed for +10g and -4.5g, while the Continental E-185 engine of 185 horsepower (hp) at takeoff (less than a third of the power of the T-6's engine) was the same as that fitted to contemporary Bonanzas.
Following the prototype were three Model A45T aircraft, the first two with the same engine as the prototype and the third with a Continental E-225, which would prove to be close to the production version. Production did not begin until 1953, when Beechcraft began delivering T-34As to the United States Air Force (USAF) and similar Model B45 aircraft for export. In 1955 production of the T-34B for the United States Navy (USN) began, this version featuring a number of differences reflecting the different requirements of the two services. The T-34B had only differential braking for steering control on the ground instead of nosewheel steering, additional wing dihedral and to cater for the different heights of pilots, adjustable rudder pedals instead of the moveable seats of the T-34A. T-34A production was completed in 1956, with T-34Bs being built until October 1957 and licensed B45 versions built in Canada (125 manufactured by Canadian Car and Foundry), Japan (173 built by Fuji Heavy Industries), and Argentina (75 by FMA) until 1958. Beechcraft delivered the last Model B45s in 1959. Total production of the Continental-engined versions in the US and abroad was 1,904 aircraft.
Model 73 Jet Mentor
In 1955 Beechcraft developed a jet-engined derivative, again as a private venture, and again in the hope of winning a contract from the US military. The Model 73 Jet Mentor shared many components with the piston-engined aircraft; major visual differences were the redesigned cockpit which was relocated further forward in the fuselage and the air intakes for the jet engine in the wing roots, supplying air to a single jet engine in the rear fuselage. The first flight of the Model 73, registered N134B, was on 18 December 1955. The Model 73 was evaluated by the USAF, which ordered the Cessna T-37, and the USN, which decided upon the Temco Pinto. The Model 73 was therefore not put into production.
Turboprop era
After a production hiatus of almost 15 years, the T-34C Turbine Mentor powered by a Pratt & Whitney Canada PT6A-25 turboprop engine was developed in 1973. Development proceeded at the behest of the USN, which supplied two T-34Bs for conversion. After re-engining with the PT6 the two aircraft were redesignated as YT-34Cs, the first of these flying with turboprop power for the first time on 21 September 1973. Mentor production re-started in 1975 for deliveries of T-34Cs to the USN and of the T-34C-1 armed version for export customers in 1977, this version featuring four underwing hardpoints. The last Turbine Mentor rolled off the production line in 1990.
