Pratt & Whitney JT9D

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JT9D
Aircraft engine IP&W JT9D.jpg
The internal structure of the JT9D
Type Turbofan
National originUnited States
Manufacturer Pratt & Whitney
First runDecember 1966
Major applications Airbus A300/A310
Boeing 747
Boeing 767
McDonnell Douglas DC-10
Number built3,200+ [1]
Developed into Pratt & Whitney PW4000

The Pratt & Whitney JT9D engine was the first high bypass ratio jet engine to power a wide-body airliner. [2] Its initial application was the Boeing 747-100, the original "Jumbo Jet". It was Pratt & Whitney's first high-bypass-ratio turbofan. [3]

Contents

Development

The Pratt & Whitney JT9D high-bypass turbofan engine was developed for the Boeing 747 P&W JT9D cutaway.jpg
The Pratt & Whitney JT9D high-bypass turbofan engine was developed for the Boeing 747

The JT9D program was launched in September 1965 and the first engine was tested in December 1966. It received its FAA certification in May 1969 and entered service in January 1970 on the Boeing 747. It subsequently powered the Boeing 767, Airbus A300 and Airbus A310, and McDonnell Douglas DC-10. The enhanced JT9D-7R4 was introduced in September 1982 and was approved for 180-minute ETOPS for twinjets in June 1985. By 2020, the JT9D had flown more than 169 million hours. Production ceased in 1990, [2] to be replaced by the new PW4000.

The JT9D was developed from the STF200/JTF14 demonstrator engines. [4] The JTF14 engine had been proposed for the C-5 Galaxy program but the production contract was awarded to the General Electric TF39. The engine's first test run took place in a test rig at East Hartford, Connecticut, with the engine's first flight in June 1968 mounted on a Boeing B-52E which served as a JT9D flying testbed. [5] In 1968, its unit cost was $800,000, [6] $7.2 million today.

Design

The JT9D introduced advanced technologies in structures, aerodynamics, and materials, which included titanium alloys and nickel alloys, to improve fuel efficiency and reliability compared to the Pratt & Whitney JT3D earlier turbofan. [2] 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. The JT9D-3, the earliest certified version of the engine, weighed 8,470 lb (3,840 kg) and produced 43,500 lbf (193 kN) thrust. [7]

Pratt & Whitney faced difficulties with the JT9D design during the Boeing 747 test program. Engine failures during the flight test program resulted in thirty aircraft being parked outside the factory with concrete blocks hanging from the pylons, awaiting redesigned engines. Boeing and Pratt & Whitney worked together in 1969 to solve the problem. The trouble was traced to ovalization, in which stresses during takeoff caused the engine casing to deform into an oval shape resulting in rubbing of high-pressure turbine blade tips. This was solved by strengthening the engine casing and adding yoke-shaped thrust links. [8]

JT9D engines powering USAF Boeing E-4A airborne command posts were designated F105.

In 1973, NAVSEA selected the JT9D-70 for use as a high efficiency gas turbine in the 30,000 hp to 50,000 hp class, installing its compressor into the pre-existing FT4 marine gas turbine to create the FT9. The engine had been recommended for provisional acceptance in June 1980, with full acceptance pending for ship-specific installation. The engine was selected by the Navy for use in Rohr Marine's 3,000 ton Surface Effect Ship, and one was to be installed aboard the vessel GTS Asiafreighter. [9] [10]

Variants

All variants have the same number of compressor and turbine stages. [11] [12]

Comp.ModelCertificationTakeoff, dryLengthWidthWeightLP rpmHP rpmT/WFan [a] Application
15-stage [11] JT9D-3AJan 9, 197043,500 lbf (193 kN)154.89 in
3.934 m		95.60 in
2.428 m		8,713 lb (3.952 t)365078504.9992.3 in
2.34 m		 Boeing 747 [13]
JT9D-7Jun 14, 197145,500 lbf (202 kN)8,880 lb (4.03 t)375080005.12
JT9D-7ASep 22, 197246,150 lbf (205.3 kN)5.2
JT9D-20Oct 16, 197244,500 lbf (198 kN)96.61 in
2.454 m		8,470 lb (3.84 t)36505.25 McDonnell Douglas DC-10 [14]
JT9D-7HJun 19, 197445,500 lbf (202 kN)95.60 in
2.428 m		8,880 lb (4.03 t)5.12 Boeing 747 [13]
JT9D-7AH46,150 lbf (205.3 kN)5.2
JT9D-7FSep 30, 197446,750 lbf (208.0 kN)37505.26
JT9D-7FWAug 2, 198250,000 lbf (220 kN)5.63
JT9D-7JAug 31, 197648,650 lbf (216.4 kN)5.48
JT9D-20JDec 29, 198648,050 lbf (213.7 kN)96.61 in
2.454 m		8,580 lb (3.89 t)5.6
16-stage [12] JT9D-59ADec 12, 197451,720 lbf (230.1 kN)154.256 in
3.9181 m		97.03 in
2.465 m		9,140 lb (4.15 t)378080115.6693.6 in
2.38 m		 McDonnell Douglas DC-10 [14]
Airbus A300 [15]
JT9D-70A51,140 lbf (227.5 kN)9,155 lb (4.153 t)5.59 Boeing 747 [13]
JT9D-7QOct 31, 197851,900 lbf (231 kN)9,295 lb (4.216 t)388880005.58
JT9D-7Q3Oct 22, 197939605.58
JT9D-7R4DNov 25, 198048,000 lbf (210 kN)96.00 in
2.438 m		8,935 lb (4.053 t)37705.3793.4 in
2.37 m		 Boeing 767 [16]
JT9D-7R4D1Apr 1, 19818,915 lb (4.044 t)38105.38 Airbus A310 [15]
JT9D-7R4E50,000 lbf (220 kN)37705.61 Boeing 767 [16]
JT9D-7R4E1154.295 in
3.9191 m		8,935 lb (4.053 t)38105.6 Airbus A310 [15]
JT9D-7R4G2Jul 23, 198254,750 lbf (243.5 kN)9,170 lb (4.16 t)382580805.97 Boeing 747 [13]
JT9D-7R4H156,000 lbf (250 kN)8,915 lb (4.044 t)38106.28 Airbus A300-600 [15]
JT9D-7R4E4Mar 29, 198550,000 lbf (220 kN)8,935 lb (4.053 t)5.6 Boeing 767 [16]

Applications

Specifications (JT9D-7R4)

Data from Pratt & Whitney [2]

General characteristics

Components

Performance

See also

Related development

Comparable engines

Related lists

References

  1. ↑ "Commercial Engines / JT9D". Pratt & Whitney.
  2. 1 2 3 4 "JT9D" (PDF). Pratt & Whitney.
  3. ↑ Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN   1-85260-163-9, p.126.
  4. ↑ The Engines of Pratt & Whitney: A Technical History, Jack Connors, ISBN   978 1 60086 711 8, p.409
  5. ↑ The Engines of Pratt & Whitney: A Technical History, Jack Connors, ISBN   978 1 60086 711 8, p.412
  6. ↑ Aero Engines 1968 Flight International 4 January 1968
  7. ↑ The Engines of Pratt & Whitney A Technical History, Jack Connors, ISBN   978 1 60086 711 8, Table 3
  8. ↑ Flight International, 13 November 1969, p.749
  9. ↑ Groghan, D. A., Miller, C. L (1981). Development of FT9 Marine Gas Turbine (PDF). Paper Number 81-GT-197. The American Society of Mechanical Engineers.
  10. ↑ Fairbanks, John W. (December 1975). "The FT9 Marine Gas Turbine Engine Development Program". Naval Engineers Journal: 79–96.
  11. 1 2 "Type Certificate data sheet Number E20EA" (PDF). FAA. February 10, 2000. Archived from the original (PDF) on January 12, 2016. Retrieved March 26, 2020.
  12. 1 2 "Type Certificate data sheet Number E3NE" (PDF). FAA. July 25, 2019. Archived from the original (PDF) on March 26, 2020. Retrieved March 26, 2020.
  13. 1 2 3 4 "Type Certificate Data Sheet NO. A20WE" (PDF). FAA. February 27, 2015. Archived from the original (PDF) on December 25, 2016. Retrieved March 26, 2020.
  14. 1 2 "Type Certificate Data Sheet A22WE" (PDF). FAA. April 30, 2018. Archived from the original (PDF) on December 2, 2018. Retrieved March 26, 2020.
  15. 1 2 3 4 "Type certificate data sheet A.172 for Airbus A300, A310 and A300-600" (PDF). EASA. 11 March 2019. Archived from the original (PDF) on 16 March 2019. Retrieved 26 March 2020.
  16. 1 2 3 "Type Certificate Data Sheet No. A1NM" (PDF). June 20, 2016. Archived from the original (PDF) on September 29, 2018. Retrieved March 26, 2020.
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