The Pratt & Whitney Canada JT15D is a small turbofan engine built by Pratt & Whitney Canada. It was introduced in 1971 at 2,200 lbf (9,800 N) thrust, and has since undergone a series of upgrades to just over 3,000 lbf (13 kN) thrust in the latest versions. It is the primary powerplant for a wide variety of smaller jet aircraft, notably business jets.
Design and development
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.[1] The fan for the original JT15D-1 was aerodynamically scaled to 75 lb/sec using the much larger JT9D fan.[2]
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.[3] 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.[4][5]
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.