The Pratt & Whitney JT12, (US military designation J60) is a small turbojet engine. The Pratt & Whitney T73 (Pratt & Whitney JFTD12) is a related turboshaft engine. Design and development The J60 conception and project design began in July 1957 at United Aircraft of Canada (now Pratt & Whitney Canada) in Montreal. The project design details were transferred to the main P&W company in East Hartford and in May 1958, the first prototype, with military designation YJ60-P-1 commenced testing. Flight tests were completed in early 1959; followed by the delivery of the new JT12A-5 engines in July 1959. These were for the two Canadair CL-41 prototype trainers with a rating of 12.9 kN (2,900 lb st). The modified JT12A-3 turbojets with a basic rating of 14.69 kN (3,300 lb st) were tested in the two Lockheed XV-4A Hummingbird VTOL research aircraft. The next version, JT12A-21, had an afterburner which delivered a maximum thrust of 17.91 kN (4,025 lb st). Variants Data from Janes YJ60-P-1prototype J60-P-3 J60-P-3A J60-P-4 J60-P-5 J60-P-6 J60-P-9 T73 Military designation of the Pratt & Whitney JFTD12 free power turbine turboshaft version of the J60. JT12A-3LH JT12A-5(J60-P-3 / -3A / -5 / -6 / -9) Take-off ratings from to . JT12A-6Essentially similar to the -5 JT12A-6A JT12A-7(J60-P-4) up-rated to JT12A-8 JT12A-8A JT12A-21An after-burning version developing thrust wet. FT12 Turboshaft versions for marine use. JFTD12 Company designation of the Pratt & Whitney T73 free power turbine turbo-shaft version of the J60. Applications Civilian (JT12) Lockheed JetStar North American Sabreliner Aérotrain Experimental 02 (French Touch in 60') Military (J60) Lockheed XH-51 Lockheed XV-4 Hummingbird Martin/General Dynamics RB-57F Canberra North American T-2B Buckeye North American T-39 Sabreliner Sikorsky S-69 Specifications (JT12A-8A) See also References External links Pratt & Whitney J60 Atlantic Canadian Aviation: JT12 for Canadair aircraft 1950s turbojet engines JT12 Pratt & Whitney Canada aircraft engines