Pratt & Whitney JT9D

JT9D
The internal structure of the JT9D.
Type Turbofan
Manufacturer Pratt & Whitney
First run December 1966
Major applications Boeing 747
Boeing 767
Airbus A310
McDonnell Douglas DC-10



The Pratt & Whitney JT9D engine was the first high bypass ratio jet engine to power a wide-body airliner. Its initial application was the Boeing 747-100, the original "Jumbo Jet". It was the company's first high-bypass-ratio turbofan.[1]

Design and development

The JT9D was developed as part of the design phase of the C-5 Galaxy. A contract was awarded to Pratt & Whitney to study the type of large engine needed, but the production contract was eventually awarded to General Electric and their TF39 turbofan. The JT9D was, however, chosen by Boeing to power the 747, with that aircraft's first flight taking place on 9 February 1969. Flight testing of the engine had begun in June 1968, using a Boeing B-52E as a testbed.

The JT9D-3, which entered service in 1970, was constructed using titanium and nickel alloys. The engine featured a single-stage fan, a three-stage low-pressure compressor and an eleven-stage high-pressure compressor coupled to a two-stage high-pressure turbine and four-stage low-pressure turbine. This version of the JT9D weighed 8,608 lb (3,905 kg) and produced 43,500 lbf (193,000 N) thrust. Production ceased in 1990.

JT9D engines powering USAF E-4A airborne command posts are designated Pratt & Whitney F105.

Pratt & Whitney's designated successor to the JT9D family is the PW4000, which features fewer parts, greater reliability, and lower base selling price.

The Pratt & Whitney JT9D high-bypass turbofan engine was developed for the 747.

Applications

Specifications (JT9D-7 series)

Data from [2]

General characteristics

Components

Performance

The JT9D Family
Model Static Thrust Basic Engine Weight Length Fan Diameter Application
JT9D-3A 45,800 lbf (203.73 kN) 8,608 lb (3,905 kg) 128.2 in (3,260 mm) 92.3 in (2,340 mm) Boeing 747-100
JT9D-7 47,900 lbf (213.07 kN) 8,850 lb (4,010 kg) 128.2 in (3,260 mm) 92.3 in (2,340 mm) Boeing 747
JT9D-20 49,400 lbf (219.74 kN) 8,450 lb (3,830 kg) 128.2 in (3,260 mm) 92.3 in (2,340 mm) McDonnell Douglas DC-10/Boeing 747
JT9D-7Q/7Q3 53,000 lbf (235.76 kN) 9,295 lb (4,216 kg) 132.1 in (3,360 mm) 93.6 in (2,380 mm) Boeing 747
JT9D-59A/70A 53,000 lbf (235.76 kN) 9,155 lb (4,153 kg) 132.2 in (3,360 mm) 93.6 in (2,380 mm) McDonnell Douglas DC-10/Boeing 747/Airbus A300
JT9D-7R4D/D1 48,000 lbf (213.51 kN) 8,905 lb (4,039 kg) 132.7 in (3,370 mm) 93.4 in (2,370 mm) Boeing 767/Airbus A310
JT9D-7R4G2 54,750 lbf (243.54 kN) 8,935 lb (4,053 kg) 132.7 in (3,370 mm) 93.4 in (2,370 mm) Boeing 747
JT9D-7R4H1 56,000 lbf (249.10 kN) 8,885 lb (4,030 kg) 132.7 in (3,370 mm) 93.4 in (2,370 mm) Airbus A300

See also

Related development
Comparable engines
Related lists

References

Notes

  1. ↑ Gunston 1989, p.126.
  2. ↑ "JT9D ENGINE". Retrieved 5 January 2014.
  3. ↑ "Thrust Data for Performance Calculations" (pdf). Figure D9. Retrieved 5 January 2014.

Bibliography

  • Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9

External links

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