Pratt & Whitney Canada JT15D

The Pratt & Whitney Canada JT15D is a small turbofan engine built by Pratt & Whitney Canada. It was introduced in 1971 at thrust, and has since undergone a series of upgrades to just over 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. 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

Specifications (JT15D-5D)

Engine	Takeoff thrust	Continuous thrust	Length	Fan Diameter	Diameter.	Dry weight	Bypass ratio
JT15D-1	9.8	9.3	1506		691	223.5	3.3
JT15D-4	11.12	10.56	1600		686	253	2.6
JT15D-4C	11.12	10.56	1600		686	261	2.6
JT15D-5	12.92		1600			287	2
JT15D-5A	12.92		1600			287	2
JT15D-5B	12.92		1600			292	2
JT15D-5C	14.21		1600			302	2
JT15D-5D	13.56		1531	520	686	292.6	3.3
JT15D-5F	12.92		1600			288	2