Lycoming ALF 502
| ALF 502/LF 507 | |
|---|---|
ALF 502 removed from a Bombardier Challenger 600-1A11 | |
| Type | Geared turbofan |
| National origin | United States |
| Manufacturer | |
| First run | June 1971[1]:â191â |
| Major applications | |
| Number built | 1,843 |
| Developed from | Lycoming T55 |

The Lycoming ALF 502/LF 507 (later Honeywell ALF 502/LF 507) is a geared turbofan engine produced by Lycoming Engines, AlliedSignal, and Honeywell Aerospace. The U.S. military designation for the ALF 502 is YF102.
Development
[edit]In mid-1970, Avco Lycoming was advertising two Lycoming T55-derived engines, an LTC4B-12 turboprop and an ALF 502A turbofan, as possible powerplants for the U.S. Air Force's A-X close air support aircraft program.[2] Northrop Corporation signed a contract with Avco Lycoming to use the ALF 502A for its entry into the A-X competition, the Northrop YA-9, in January 1971. The engine was given a United States military aircraft engine designation of YF102-LD-100.[1]:â190â Six YF102 engines were built for the YA-9. The 7,500Â lbf (33Â kN) thrust engines powered the A-9A prototypes for seven months of flight tests in 1972, recording 238 flights and 652 flight hours.[3] These engines were later reused in the C-8A Quiet Short-Haul Research Aircraft (QSRA).
The commercial ALF 502D engine was developed from the military YF102 in 1971. Its 6,500Â lbf (29Â kN) derated engine had just one booster compressor stage instead of the YF102's two stages, and operated under a lower turbine temperature to improve reliability. The ALF 502D powered the Dassault Falcon 30 prototype from May 1973 into 1975, logging 270 flight hours until Dassault discontinued development of the aircraft model. The ALF 502D was also chosen for the LearStar 600 executive transport aircraft, which eventually became the Canadair CL-600 Challenger. The CL-600 Challenger first flew in November 1978 and was powered by the 7,500Â lbf (33Â kN) ALF 502L-2, ALF 502L-2A, and ALF 502L-3 variants. The 6,700Â lbf (30Â kN) ALF 502R-3 variant initially powered the quad-engine British Aerospace 146, which entered service in 1983 and became the ALF 502's biggest customer. A total of 1,019 ALF 502 engines of all variants were produced. The LF 507 series based on the ALF 502R was announced in September 1988. The series initially consisted of the hydromechanically controlled LF 507-1H and the FADEC-controlled LF 507-1F, both offering 7,000Â lbf (31Â kN) of thrust. Both variants were used on the Avro RJ update of the BAe 146, and the LF 507-1F was also used on the BAe 146.[1]:â192â199,â203â 818 LF 507 engines were produced.[4]
In 2020, Honeywell sold the type certificate to CFS Aeroproducts Inc. (Arizona), a subsidiary of MRO provider CFS Aeroproducts Ltd (UK), then transferred in January 2021.[5]
Proposed variants
[edit]In 1972, Lycoming and NASA published a study describing the ALF504, a 12.5 bypass ratio engine producing 8,370Â lbf (3,800Â kgf; 37.2Â kN) of sea-level thrust at a specific fuel consumption of 0.302Â lb/(lbfâ h) (8.6Â g/(kNâ s)) and a fan tip diameter of 48.0Â in (1,220Â mm).[6]
Lycoming announced its LF500 family of turbofans in September 1988, starting with the LF507-1H and LF507-1F, which were certificated in October 1991 and March 1992, respectively.[1]:â198â In June 1992, the company outlined improvements to the LF500 family's core, which included a wide-chord fan to move more air, uprated fan gearbox, three-stage power turbine (an increase from two stages), more lighter-weight composite materials, increased diameter in the first three stages of the axial compressor to increase airflow by 17 percent, an improved impeller (centrifugal compressor) with lean-back vanes, a 16-lobe forced exhaust mixer to reduce noise and specific fuel consumption (SFC), an advanced combustor, and a temperature margin increase of 248 °F (120 °C) in the turbine.[7] Lycoming introduced the 500 Series of common core engines of turboprops and turbofans in February 1994 as a derivative of the LF507 to power regional aircraft in the late 1990s.[1]:â198,â199,â200â A turboprop version also was planned for the European Future Large Aircraft military transport (which would eventually become the Airbus A400M). AlliedSignal, which took over Lycoming in October 1994,[8] demonstration tested the common core in December; the core was capable of producing 20,000 lbf (89 kN) of thrust.[9] After losing the competition to power the de Havilland Dash 8-400 regional turboprop, AlliedSignal abandoned the common core effort in July 1995.[10]
Design
[edit]
The ALF502 is a high bypass turbofan with geared fan, axial-centrifugal flow high pressure compressor, reverse flow annular combustor, two-stage high pressure turbine, two-stage low pressure turbine.[11]
Variants
[edit]- ALF502R-3 (single-stage LP compressor)
- ALF502R-4: R-3 with higher thrust
- ALF502R-5: R-4 with improved first-stage and second-stage turbine nozzle assemblies
- ALF502R-3A: R-3 with gas producer turbine improvements, but operated at higher thrust
- ALF502L (two-stage LP compressor)
- ALF502L-2: L with fan blade modification for increased altitude performance
- ALF502L-3: L-2 with turbine improvements and automatic power reserve features
- ALF502L-2A: L-2 with gas producer turbine improvements and automatic power reserve features
- ALF502L-2C: L-2A without automatic power reserve
- ALF502R-6: L-2C with R-5 accessory gearbox
- LF507-1H: R-6 with lower, flat-rated thrust
- LF507-1F: 507-1H with a single-channel FADEC with hydromechanical backup
Proposed Common Core engines
[edit](LF500 family/Lycoming 500 Series/AlliedSignal AS800)
- LF508B2: A 7,900Â lbf thrust (35Â kN) engine offered for the quad-turbofan powered, 120-seat British Aerospace Regional JetLiner (formerly BAe 146) in 1992[7]
- LF509: A 9,000Â lbf thrust (40Â kN) turbofan engine for the Avro RJ100[12]
- LF511D: An 11,000Â lbf thrust (49Â kN) turbofan with a 43Â in diameter (1.09Â m) wide-chord fan, a three-stage power turbine, and a three-stage low-pressure booster compressor[7]
- LF512 / LF514: Additional turbofan engines of 12,000â14,000Â lbf (53â62Â kN) thrust, possibly for Avro's proposed 120-seat RJX twin airliner or for a stretched version of the 50-seat Canadair Regional Jet[12]
- LF518: An 18,000Â lbf (80Â kN) turbofan variant.[13]
- LP512: Turboprop engines targeted for the de Havilland Dash 8-400 and the proposed ATR 82, having an initial power output of 7,500Â shp (5,600Â kW) but with uprate capability to 11,000Â shp (8,200Â kW)[1]:â200â
Applications
[edit]
- YF102
- ALF 502
- Bombardier Challenger 600: early CL-600 (1A11) series, 81 built from 1978 to 1982
- British Aerospace 146
- Dassault Falcon 30 (prototype)
- LF 507
- Avro RJ
- British Aerospace 146
- Yakovlev Yak-40TL (proposed reengine)[14]
Specifications
[edit]| Variant | ALF502R-3 | ALF502R-4/5/3A | ALF502L/L-2/L-3/L-2A/L-2C/R-6 | LF507-1H/1F | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Configuration | High bypass, geared fan | |||||||||||
| Fan diameter | 40.25Â in (1,022Â mm)[15] | |||||||||||
| Gear ratio | 2.3:1[16] | |||||||||||
| Bypass ratio | 5.7:1 | |||||||||||
| Compressor | 1 LP, 7-stage axial[15] + centrifugal HP | 2 LP, 7-stage axial[15] + centrifugal HP | ||||||||||
| Combustor | Reverse flow annular | |||||||||||
| Turbine | Two-stage HP, two-stage LP | |||||||||||
| Takeoff thrust | 6,700Â lbf (30Â kN) | 6,970Â lbf (31.0Â kN) | 7,500Â lbf (33Â kN) | 7,000Â lbf (31Â kN) | ||||||||
| Length | 63.66Â in (1,617Â mm) | 65.57Â in (1,665Â mm) | ||||||||||
| Height | 55.5Â in (1,410Â mm) | 54.5Â in (1,380Â mm) | ||||||||||
| Width | 47.8Â in (1,210Â mm) | 48.6Â in (1,230Â mm) | ||||||||||
| Weight [a] | 1,336Â lb (606Â kg) | 1,375Â lb (624Â kg) (1F: 1,385Â lb (628Â kg)) | ||||||||||
| LP rpm | 7,184 - 7,374 | |||||||||||
| HP rpm | 19,280 - 19,760 | |||||||||||
| TSFC (SLS ISA) | 0.406Â lb/(lbfâ h) (11.5Â g/(kNâ s))[15] | |||||||||||
| Thrust/weight | 5.01 | 5.22 | 5.45 | 5.09 | ||||||||
See also
[edit]Related development
- Lycoming T55
- Honeywell HTF7000 (AS907), ALF502/LF507 successor
Comparable engines
Geared turbofans
Related lists
Notes
[edit]- â includes essential engine accessories but excludes starter, hydraulic pump, integrated drive generator and exhaust nozzle
References
[edit]- 1 2 3 4 5 6 Leyes, Richard A., II; Fleming, William A. (1999). The history of North American small gas turbine aircraft engines. Reston, VA: National Air and Space Museum and American Institute of Aeronautics and Astronautics (AIAA). ISBNÂ 1-56347-332-1. OCLCÂ 247550535.
{{cite book}}: CS1 maint: multiple names: authors list (link) - â Avco Lycoming Division (July 1970). "Proven power, turbofan or turboprop, for any AX configuration". Air Force Magazine. p. 45. ISSN 0730-6784.
- â Anderson, Fred (1976). "A-X / A-9A close air support aircraft". Northrop: An aeronautical history. Wipf & Stock Publishers. pp. 251â256. ISBN 9781532601460. OCLC 980678030.
- â Learmount, David; Norris, Guy (August 16, 2004). "Uncontained failure dogs Honeywell LF507 engine". Flight International. ISSNÂ 0015-3710. Retrieved January 30, 2022.
- â "CFS Aeroproducts Inc. Chooses ATP as Exclusive Partner for ALF502 and LF507 Series Engine Publications" (Press release). ATP. July 27, 2021.
- â Rauch, Dale (July 1972). Design study of an air pump and integral lift engine ALF-504 using the Lycoming 502 core (Report). National Aeronautics and Space Administration (NASA). hdl:2060/19730004744. alternate url
- 1 2 3 Warwick, Graham (June 17, 1992). "Lycoming outlines LF500 power increase". Flight International. Vol. 141, no. 4323. p. 8. ISSN 0015-3710. Gale A12271580.
- â Kandebo, Stanley (November 7, 1994). "AlliedSignal completes Lycoming acquisition". Aviation Week & Space Technology. Vol. 141, no. 19. p. 35. ISSN 0005-2175.
- â "AlliedSignal runs demo test on former Lycoming 'Common Core' engine". Commuter Regional Airline News. Vol. 12, no. 50. December 26, 1994. pp. 6+. ISSN 1040-5402. Gale A16362047.
- â "AlliedSignal plans turbine closure". FlightGlobal. July 11, 1995. Retrieved July 16, 2020.
- 1 2 "Type certificate data sheet E6NE" (PDF) (15th ed.). Department of Transportation, Federal Aviation Administration (FAA). June 7, 2002. Archived from the original (PDF) on April 19, 2022. Retrieved July 25, 2020.
- 1 2 "Textron Lycoming studies 9,000 lb-thrust LF509 for 'developed' RJ100". Commuter Regional Airline News. Vol. 12, no. 28. July 18, 1994. p. 2. ISSN 1040-5402. Gale A15618034.
- â Sweetman, Bill (October 1994). "New power for regionals". Finance, markets & industry. Interavia. Vol. 49, no. 583. Minneapolis, Minnesota, U.S.A. pp. 16â18. ISSN 1423-3215. OCLC 199793280.
- â Donoghue, J.A.; Moorman, Robert W.; Reed, Arthur; Woolsey, James P. (October 1992). "Russian deals at Farnborough". Air Transport World. Vol. 29, no. 10. pp. 36+. ISSN 0002-2543. Gale A12736619.
- 1 2 3 4 "ALF 502 turbofan engine". Honeywell Aerospace. November 29, 2010. Archived from the original on March 5, 2012.
- â Warwick, Graham (25 August 1993). "Engine for change". Flight International. Vol. 144, no. 4384. pp. 39+. ISSN 0015-3710. Gale A14335274.
Further reading
[edit]- Whitaker, Richard (January 30, 1982). "ALF502: Plugging the turbofan gap". Flight International. Cutaway by Frank Munger. pp. 237â241. ISSN 0015-3710. Archived from the original on December 31, 2022. Retrieved December 30, 2022.
- The ALF 502R turbofan: Technology, ecology, economy. Avco Lycoming Textron (brochure). Archived from the original on December 31, 2022. Retrieved December 30, 2022.