Pratt & Whitney F100

F100
F100 for an F-15 Eagle being tested
Type	Turbofan
National origin	United States
Manufacturer	Pratt & Whitney
First run	1970s
Major applications	F-15 Eagle F-15E Strike Eagle F-16 Fighting Falcon Northrop Grumman X-47B
Developed into	Pratt & Whitney PW1120

The Pratt & Whitney F100 (company designation JTF22^[1]) is an afterburning turbofan engine manufactured by Pratt & Whitney which powers the F-15 Eagle and F-16 Fighting Falcon.

Development

In 1967, the United States Navy and United States Air Force teamed up to invite engine proposals for F-14 Tomcat and F-15 Eagle fighters. The combined program was called Advanced Turbine Engine Gas Generator (ATEGG) with goals to improve thrust and reduce weight to achieve a thrust-to-weight ratio of 9. The program requested proposals and would award Pratt & Whitney a contract in 1970 to produce F100-PW-100 (USAF) and F401-PW-400 (USN) engines. The Navy would cut back and later cancel its order, choosing to continue to use the Pratt & Whitney TF30 engine from the F-111 in its F-14.^[2]

Variants

F100-PW-100

F100-PW-100 on display at the Virginia Air and Space Center

The F100-100 first flew in an F-15 Eagle in 1972 with a thrust of 23,930 lb_f. Due to the advanced nature of engine and aircraft, numerous problems were encountered in its early days of service including high wear, stalling^[3] and "hard" afterburner starts which are commonly referred to as A/B blowouts by the Air Force mechanics who service the engines.^{[citation needed]} These "hard" starts could be caused by failure of the afterburner to start or by extinguishing after start, in either case the large jets of jet fuel were lit by the engine exhaust resulting in high pressure waves causing the engine to stall. Early problems were solved, and the F100 is still in the USAF fleet to this day.

The manner in which the early problems were solved on the F100 during the early to mid-1970s provided an example of larger concerns about the nature of the partnership of the U.S. government with for-profit industrial corporations in the field of research and development (R&D). Since World War II, technological innovation through R&D has been a necessary part of maintaining military advantage; thus it is part of national security policy. But if industries such as aerospace and electronics are not nationalized (which they are not in the United States and many other countries), and for-profit corporations are to be part of the mix (some advantages being competition and the efficiency and innovation that it engenders), then there are inherent questions to consider about the side effects of a military–industrial complex, such as who pays the costs (and takes the risks) of technological advancement—including routine R&D, correction of deficiencies in initial design (a.k.a. "rework"), the natural teething pains of new technology (e.g., rockets' exploding on the launchpad being an inevitable part of life despite anyone's best efforts^[4]), and so on. Clearly neither the government nor the private sector can underwrite all of these costs, because if government bears too much of the expenses, then private companies benefit unfairly from public tax dollars, whereas if the private sector were expected to provide too much of the capital, the pace of advancement would be restricted if individual corporations avoided large risks (big bets on particular technologies or product lines). The concepts of sales to foreign governments potentially undermining U.S. military advantage, "excess profits", and "warmongering" also enter the equation (including, in the latter two cases, how even to define them, or to differentiate them from their defensible, milder analogues). In a history of Pratt & Whitney's parent corporation United Technologies, Ronald Fernandez (1983)^[5] discussed how some of these larger themes played out in relation to particular programs such as the F100,^[3] where reengineering and testing incurred substantial costs.

F100-PW-200

The F-16 Fighting Falcon entered service with the F100-200, with only slight differences from the -100. Seeking a way to drive unit costs down the USAF implemented the Alternative Fighter Engine (AFE) program in 1984, under which the engine contract would be awarded through competition. The F-16C/D Block 30/32s were the first to be built with the common engine bay, able to accept the existing engine or the General Electric F110.

F100-PW-220/220E

The F100-PW-220 incorporated the most advanced technology available, including the precision control and advanced maintenance features of digital electronic controls and the extended durability and reliability of metallurgical and heat-transfer advances. The F100-220 was introduced in 1986 and could be installed on either an F-15 or F-16.^{[citation needed]} A non-afterburning variant, the F100-PW-220U powers the Northrop Grumman X-47B UCAV. The F100-220E is a -200 engine upgraded to -220 specification.^{[citation needed]}

F100-PW-229

Using technology developed from the F119 and F135 engine programs for the F-22 Raptor and F-35 Lightning II,^{[citation needed]} the current production F100-PW-229 incorporates modern turbine materials, cooling management techniques, compressor aerodynamics, and electronic controls. The first -229 was flown in 1989 and has a thrust of 17,800  lbs (dry thrust) and 29,160  lbs with afterburner. It currently powers late model F-16s and F-15E Strike Eagle.

Applications

An F401 engine for Rockwell XFV-12 prototype supersonic VTOL fighter

F100

• McDonnell Douglas F-15 Eagle
• McDonnell Douglas F-15E Strike Eagle
• General Dynamics F-16 Fighting Falcon
• Northrop Grumman X-47B

F401

• Grumman F-14B Tomcat (planned; test aircraft only)
• Rockwell XFV-12

Specifications (F100-PW-229)

Data from ^[6]

General characteristics

• Type: Afterburning turbofan
• Length: 191 in (4,851 mm)
• Diameter: 34.8 in (884 mm) inlet, 46.5 in (1,181 mm) maximum external
• Dry weight: 3,740 lb (1,696 kg)

Components

• Compressor: Dual Spool Axial compressor with 3 fan and 10 compressor stages
• Bypass ratio: 0.36:1
• Combustors: annular
• Turbine: 2 low-pressure and 2 high-pressure stages

Performance

• Maximum thrust: *17,800 lbf (79.1 kN) military thrust
  • 29,160 lbf (129.6 kN) with afterburner
  • Overall pressure ratio: 32:1
  • Specific fuel consumption: *Military thrust: 0.76 lb/(lbf·h) (77.5 kg/(kN·h))
  • Full afterburner: 1.94 lb/(lbf·h) (197.8 kg/(kN·h))
  • Thrust-to-weight ratio: 7.8:1 (76.0 N/kg)

See also

Related development

• Pratt & Whitney PW1120
  

Comparable engines

• General Electric F110
• Saturn AL-31
• Shenyang WS-10
• Snecma M53
  

Related lists

• List of aircraft engines
  

References

1. ^ Designation-systems.net's Designations Of U.S. Military Aero Engines page
2. ^ Davies, Steve. Combat Legend, F-15 Eagle and Strike Eagle. London: Airlife Publishing, Ltd., 2002. ISBN 1-84037-377-6.
3. ^ ^{a b} Fernandez 1983, pp. 241–245, 251–254
4. ^ Fernandez 1983, p. 208.
5. ^ Fernandez 1983.
6. ^ [1]^{[dead link]}

Bibliography

• Fernandez, Ronald (1983), Excess profits: the rise of United Technologies, Boston, Massachusetts, USA: Addison-Wesley, ISBN 9780201104844. 

External links

• F100 page on Pratt & Whitney's site
• F100-PW-100/-200 page on GlobalSecurity.com
• F100 page on LeteckeMotory.cz (cs)