"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 920 lbf (4.1 kN) Continental J69 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 TT Pinto. After initial testing at the Naval Air Test Center at NAS Patuxent River, Maryland, the Navy tested the feasibility of using the TT Pinto as a jet-powered trainer for primary flight training in 1959, but discontinued use of the aircraft by December 1960 and discarded all examples, returning to the piston-powered T-34B Mentor and North American T-28 Trojan for its primary flight training requirements. The Beechcraft Model 73 was not put into production and the sole prototype is displayed at the Kansas Aviation Museum."