# 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 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. 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-4

    Introduced in 1973, improving thrust to 2,500 lbf (11,000 N). 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-5

    Certified in 1983. The first versions delivered 2,900 lbf (13,000 N) 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-5D

    Certified in 1993, increased thrust again, this time to 3,045 lbf (13,540 N). The -5D is used on the Cessna UC-35A and Cessna Citation Ultra.

### JT15D-5F
## Applications

* 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)
#### General characteristics

* Type: Turbofan
* Length: 60.3 in (1,530 mm)
* Diameter: 27 in (690 mm)
* Dry weight: 630 lb (290 kg)

#### Components

* Compressor: Axial flow LP, centrifugal flow HP
* Fuel type: Jet A/A1

#### Performance

* Maximum thrust: 3,050 lbf (1,380 kgf; 13.6 kN)
* Specific fuel consumption: 0.562 lb/(lbf⋅h) (15.9 g/(kN⋅s)) at maximum thrust; 0.552 lb/(lbf⋅h) (15.6 g/(kN⋅s)) at cruise (typical)
* Thrust-to-weight ratio: ≈ 4.58
| Engine | Takeoff thrust (kN) | Continuous thrust (kN) | Length (mm) | Fan Diameter(mm) | Diameter.(mm) | Dry weight (kg) | 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 |