AJ-2 Savage test bed for Lycoming engines in flight

The Lycoming ALF 502/LF 507 (now:Honeywell ALF 502/LF 507) is a

geared turbofan The geared turbofan is a type of turbofan aircraft engine, with a gearbox between the fan and the low pressure shaft to spin each at optimum angular velocities. Technology In a conventional turbofan, a single shaft (the "low-pressure" or LP sh ...

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

produced by

Lycoming Engines Lycoming Engines is a major American manufacturer of aircraft engines. With a factory in Williamsport, Pennsylvania, Lycoming produces a line of horizontally opposed, air-cooled, four, six and eight-cylinder engines including the only FAA-cer ...

AlliedSignal AlliedSignal was an American aerospace, automotive and engineering company created through the 1985 merger of Allied Corp. and Signal Companies. It subsequently purchased Honeywell for $14.8 billion in 1999, and thereafter adopted the Honeywell ...

, and then

Honeywell Aerospace Honeywell Aerospace is a manufacturer of aircraft engines and avionics, as well as a producer of auxiliary power units (APUs) and other aviation products. Headquartered in Phoenix, Arizona, it is a division of the Honeywell International conglom ...

Development

In mid-1970, Avco Lycoming was advertising two

Lycoming T55 The Honeywell T55 (formerly Lycoming; company designation LTC-4) is a turboshaft engine used on American helicopters and fixed-wing aircraft (in turboprop form) since the 1950s, and in unlimited hydroplanes since the 1980s. Today, there have ...

-derived engines, an LTC4B-12 turboprop and an ALF 502A turbofan, as possible powerplants for the

U.S. Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sign ...

's A-X

close air support In military tactics, close air support (CAS) is defined as air action such as air strikes by fixed or rotary-winged aircraft against hostile targets near friendly forces and require detailed integration of each air mission with fire and movemen ...

aircraft program.

Northrop Corporation Northrop Corporation was an American aircraft manufacturer from its formation in 1939 until its 1994 merger with Grumman to form Northrop Grumman. The company is known for its development of the flying wing design, most successfully the B-2 Sp ...

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. Six YF102 engines were built for the YA-9. The thrust engines powered the A-9A prototypes for seven months of

flight test Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing aircraft behaviour and systems. Instrumentation systems are developed using proprietary transducers and data acquisition systems. D ...

s in 1972, recording 238 flights and 652 flight hours. 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 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 The Dassault Falcon 20 is a French business jet developed and manufactured by Dassault Aviation. The first business jet developed by the firm, it became the first of a family of business jets to be produced under the same name; of these, both t ...

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 The Bombardier Challenger 600 series is a family of business jets developed by Canadair after a Bill Lear concept, and then produced from 1986 by its new owner, Bombardier Aerospace. At the end of 1975, Canadair began funding the development ...

executive transport aircraft, which eventually became the

Canadair CL-600 Challenger The Bombardier Challenger 600 series is a family of business jets developed by Canadair after a Bill Lear concept, and then produced from 1986 by its new owner, Bombardier Aerospace. At the end of 1975, Canadair began funding the development ...

. The CL-600 Challenger first flew in November 1978 and was powered by the ALF 502L-2, ALF 502L-2A, and ALF 502L-3 variants. The ALF 502R-3 variant initially powered the quad-engine

British Aerospace 146 The British Aerospace 146 (also BAe 146) is a short-haul and regional airliner that was manufactured in the United Kingdom by British Aerospace, later part of BAE Systems. Production ran from 1983 until 2001. Manufacture by Avro International ...

, which entered service in 1983 and became the ALF 502's biggest customer. 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 A full authority digital engine (or electronics) control (FADEC) is a system consisting of a digital computer, called an "electronic engine controller" (EEC) or "engine control unit" (ECU), and its related accessories that control all aspects of ai ...

-controlled LF 507-1F, both offering of thrust. Both variants were used on the

Avro RJ AVRO, short for Algemene Vereniging Radio Omroep ("General Association of Radio Broadcasting"), was a Dutch public broadcasting association operating within the framework of the Nederlandse Publieke Omroep system. It was the first public broad ...

update of the BAe 146, and the LF 507-1F was also used on the BAe 146. 818 LF 507 engines were produced. 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.

Proposed variants

In 1972, Lycoming and

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...

published a study describing the ALF504, a 12.5 bypass ratio engine producing of sea-level thrust at a specific fuel consumption of and a fan tip diameter of . 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. 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 Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), diff ...

, three-stage power

turbine A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating ...

(an increase from two stages), more lighter-weight

composite materials A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or ...

, increased diameter in the first three stages of the

axial compressor An axial compressor is a gas compressor that can continuously pressurize gases. It is a rotating, airfoil-based compressor in which the gas or working fluid principally flows parallel to the axis of rotation, or axially. This differs from other ...

to increase airflow by 17 percent, an improved

impeller An impeller or impellor is a rotor used to increase the pressure and flow of a fluid. It is the opposite of a turbine, which extracts energy from, and reduces the pressure of, a flowing fluid. In pumps An impeller is a rotating componen ...

(centrifugal compressor) with lean-back vanes, a 16-lobe forced

exhaust mixer In aviation, exhaust mixer is a feature of many turbofan engines, where the bypass (cold/slow) air is mixed with the core (hot/fast) exhaust gases, before exhausting to atmospheric pressure through a common (mixed flow) propelling nozzle. Benefi ...

to reduce noise and specific fuel consumption (SFC), an advanced

combustor A combustor is a component or area of a gas turbine, ramjet, or scramjet engine where combustion takes place. It is also known as a burner, combustion chamber or flame holder. In a gas turbine engine, the ''combustor'' or combustion chamber is f ...

, and a temperature margin increase of in the turbine. Lycoming introduced the 500 Series of common core engines of

turboprops A turboprop is a turbine engine that drives an aircraft propeller. A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. F ...

and turbofans in February 1994 as a derivative of the LF507 to power regional aircraft in the late 1990s. A turboprop version also was planned for the European

Future Large Aircraft The Airbus A400M AtlasNamed after the Greek mythological figure. is a European four-engine turboprop military transport aircraft. It was designed by Airbus Military (now Airbus Defence and Space) as a tactical airlifter with strategic capab ...

military transport (which would eventually become the

Airbus A400M The Airbus A400M AtlasNamed after the Greek mythological figure. is a European four-engine turboprop military transport aircraft. It was designed by Airbus Military (now Airbus Defence and Space) as a tactical airlifter with strategic capa ...

). AlliedSignal, which took over Lycoming in October 1994, demonstration tested the common core in December; the core was capable of producing of

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that ...

. After losing the competition to power the

de Havilland Dash 8 The De Havilland Canada DHC-8, commonly known as the Dash 8, is a series of turboprop-powered regional airliners, introduced by de Havilland Canada (DHC) in 1984. DHC was later bought by Boeing in 1988, then by Bombardier in 1992; then ...

-400 regional turboprop, AlliedSignal abandoned the common core effort in July 1995.

Design

Australian Corporate Jet Centres (VH-JPQ) Canadair CL-600-1A11 Challenger 600 taxiing at Wagga Wagga Airport (3) (cropped)

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.

Variants

; 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

(LF500 family/Lycoming 500 Series/AlliedSignal AS800) * LF508B2: A engine offered for the quad-turbofan powered, 120-seat British Aerospace Regional JetLiner (formerly

BAe 146 The British Aerospace 146 (also BAe 146) is a short-haul and regional airliner that was manufactured in the United Kingdom by British Aerospace, later part of BAE Systems. Production ran from 1983 until 2001. Manufacture by Avro Internation ...

) in 1992 * LF509: A turbofan engine for the Avro RJ100 * LF511D: An turbofan with a wide-chord fan, a three-stage power turbine, and a three-stage low-pressure booster compressor * LF512 / LF514: Additional turbofan engines of thrust, possibly for

Avro AVRO, short for Algemene Vereniging Radio Omroep ("General Association of Radio Broadcasting"), was a Dutch public broadcasting association operating within the framework of the Nederlandse Publieke Omroep system. It was the first public broa ...

's proposed 120-seat RJX twin airliner or for a stretched version of the 50-seat

Canadair Regional Jet The Bombardier CRJ or CRJ Series (for Canadair Regional Jet) is a family of regional jets introduced in 1991 by Bombardier Aerospace. The CRJ was formerly manufactured by Bombardier Aerospace with the manufacturing of the first CRJ generation, ...

* LF518: An turbofan variant. * LP512: Turboprop engines targeted for the

-400 and the proposed ATR 82, having an initial power output of but with uprate capability to

Applications

;YF102 * Northrop YA-9 * C-8A Quiet Short-Haul Research Aircraft ;ALF 502 *

Bombardier Challenger 600 The Bombardier Challenger 600 series is a family of business jets developed by Canadair after a Bill Lear concept, and then produced from 1986 by its new owner, Bombardier Aerospace. At the end of 1975, Canadair began funding the development ...

: early CL-600 (1A11) series, 81 built from 1978 to 1982 *

(prototype) ;LF 507 *

Yakovlev Yak-40 The Yakovlev Yak-40 (russian: Яковлев Як-40; NATO reporting name: Codling) is a regional jet designed by Yakovlev. The trijet's maiden flight was in 1966, and it was in production from 1967 to 1981. Introduced in September 1968, the ...

TL (proposed reengine)

Specifications

Notes

References

External links

Honeywell propulsion products page

Technical details from Swiss International Air Lines
{{USAF gas turbine engines Geared turbofan engines High-bypass turbofan engines ALF 502 ALF 502

LF507 The Lycoming ALF 502/LF 507 (now:Honeywell ALF 502/LF 507) is a geared turbofan engine produced by Lycoming Engines, AlliedSignal, and then Honeywell Aerospace. Development In mid-1970, Avco Lycoming was advertising two Lycoming T55-derived e ...

Mixed-compressor gas turbines 1980s turbofan engines