Pratt & Whitney Canada JT15D

The JT15D was first run in 1967. Its use of a centrifugal compressor as the high-pressure stage in a turbofan engine was followed in 1970 by the Garrett TFE731. The fan for the original JT15D-1 was aerodynamically scaled to 75 lb/sec using the much larger JT9D fan. About 70% of the air passing through the fan goes down the bypass duct. The JT15D-4 and later variants use a "booster" axial stage behind the fan which runs at the same speed as the fan and directs the remaining 30% of the air into the high-pressure compressor, after which it passes into a reverse-flow annular combustor. The hot gases flow through a high-pressure turbine that drives the centrifugal compressor, and a low-pressure turbine that drives the fan and booster. The engine was first run in August 1967 before being test flown on an Avro Canada CF-100 Canuck in an underslung external test pod. In 1975 a unique over-wing installation in place of Pratt & Whitney Canada PT6 turboprops was fitted to a Beechcraft Super King Air and flown for 93 hours to investigate the use of turbofan engines on that airframe. ==Variants==

;JT15D-1:The first model was introduced to power the Cessna Citation I, then known as the Fanjet 500. Deliveries started in 1972, and eventually on 1,417 -1s were delivered. ;JT15D-1A: ;JT15D-1B: ;JT15D-4:Introduced in 1973, improving thrust to . The -4 was the primary engine for the Cessna Citation II, and went on to find use on the Mitsubishi Diamond 1A, Aerospatiale Corvette and SIAI-Marchetti S.211. Eventually 2,195 engines of the -4 series were delivered. ;JT15D-4A: ;JT15D-4B: ;JT15D-4C: ;JT15D-4D: ;JT15D-5: Certified in 1983. The first versions delivered and were used on the Beechjet 400A and Cessna T-47A. Several minor versions were introduced, the -5A for the Cessna Citation V, while the -5B powered the Beechcraft T-1A Jayhawk, the -5C the DASA Ranger 2000 and S-211A. ;JT15D-5A: ;JT15D-5B: ;JT15D-5C: ;JT15D-5D: Certified in 1993, increased thrust again, this time to . The -5D is used on the Cessna UC-35A and Cessna Citation Ultra. ;JT15D-5F: ==Applications==

installation • Aérospatiale Corvette • Alenia Aermacchi M-311 • Ball-Bartoe Jetwing • Boeing Bird of Prey • Beechcraft Beechjet 400 • Cessna Citation I • Cessna Citation II • Cessna Citation V/Ultra • EADS Barracuda • Hawker 400 • Honda MH02 • Mitsubishi MU-300 Diamond • Northrop Grumman X-47A Pegasus • Raytheon T-1 Jayhawk • Rockwell Ranger 2000 • Scaled Composites 401 • Scaled Composites ARES • SIAI-Marchetti S.211/Aermacchi S-211 • Sport Jet II • Stratos 716X ==Specifications (JT15D-5D)==