Garrett ATF3
The Garrett ATF3 (US military designation F104) is a 3-spool turbofan engine developed at the California division of Garrett AiResearch. Due to mergers it is currently supported by Honeywell Aerospace. The engine is unusual as the core flow path is twice reversed 180 deg. Aft of the fan, the axial compressor has five stages, after which the gas path progresses to the aft end of the engine. There, it is reversed 180 deg and flows through a centrifugal compressor stage, the combustors and then the turbine stages. Beyond this, the flow is then reversed 180 deg again to exit in the fan bypass duct. All engine accessories are mounted on the aft end of the engine under an engine tail-cone.[1]
| ATF3 / F104 | |
|---|---|
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| A Dassault HU-25 Guardian, powered by two ATF3 engines | |
| Type | Turbofan |
| National origin | United States |
| Manufacturer | Garrett AiResearch Honeywell Aerospace |
| First run | May 1968 |
| Major applications | Dassault Falcon 20G Dassault Falcon 200 Dassault HU-25 Guardian |
| Number built | 200+ |
Design and development
The ATF3 was first flown in the Teledyne Ryan YQM-98 Compass Cope R high altitude UAV, as the YF104-GA-100. The engine proved to have a very low infrared signature, as the hot turbine was not externally visible and the core exhaust mixed with the bypass air before exiting the engine. The pilots of U-2 high altitude chase planes reported being unable pick up the YQM-98A with either radar or IR sensors.[2] It was later used in the Northrop Tacit Blue stealth demonstrator because of these characteristics.[3]
The most significant application of the engine was on the Dassault HU-25 Guardian, developed for the US Coast Guard. It was also used on the Dassault Falcon 20G and Dassault Falcon 200.[3]
The ATF3 was "selected by North American Rockwell for its new Series 60 Sabreliner business jet. . . . [H]owever, the ATF3 developed engineering and production problems. Delivery schedules were not met. North American Rockwell brought a $60 million suit against Garrett. . . . The suit was settled out of court for less than $5 million cash. The engine was ultimately selected for a version of the Dassault Falcon ordered by the U.S. Coast Guard for offshore surveillance."[4]
Applications
Specifications (ATF3/F104-GA-100)
Data from Jane's All The World's Aircraft 1988-89.[5]
General characteristics
- Type: Three shaft axial-flow turbofan
- Length: 102.0 in (2,591 mm)
- Diameter: 33.6 in (853 mm)
- Dry weight: 1,125 lb (510 kg
Components
- Compressor: Single Stage Low Pressure Fan, 5 stage intermediate pressure axial compressor and single stage high pressure centrifugal compressor
- Combustors: Reverse flow annular type
- Turbine: 3 stage: single stage High Pressure, three stage intermediate pressure and two stage Low Pressure
Performance
- Maximum thrust: 5,440 lbf (24.20 kN) - Take off, 1,055 lbf (4.69 kN) Cruise
- Overall pressure ratio: 21
- Bypass ratio: 2.8
- Air mass flow: 162 lb/s (73.5 kg/s) at take off
Citations
- ATF3 Engine Overview. Retrieved 26 June 2011
- Chronology of the ATF3. Retrieved 26 June 2011
- ATF3 Airframe Applications. Retrieved 26 June 2011
- William Schoneberger and Robert R. H. Scholl, Out of Thin Air: Garrett's First 50 Years (Los Angeles: The Garrett Corporation, 1985): pp. 175-176.
- Taylor 1982, p.777.
References
- Gunston, Bill (2006). World Encyclopedia of Aero Engines, 5th Edition. Phoenix Mill, Gloucestershire, England, UK: Sutton Publishing Limited. ISBN 0-7509-4479-X.
- Taylor, John W R (1988). Jane's All The World's Aircraft 1988-89. Coulsdon, Surrey, UK: Jane's Information Group. ISBN 0-7106-0867-5.
- Taylor, John W R (1982). Jane's All The World's Aircraft 1982-83. Coulsdon, Surrey, UK: Jane's Information Group. ISBN 0-7106-0748-2.