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ALF 502/LF 507
ALF 502 removed from a Bombardier Challenger 600-1A11
Type Geared turbofan
United States
Manufacturer Lycoming Engines
Honeywell Aerospace
First run 1980
Bombardier Challenger 600
British Aerospace 146
Northrop YA-9
The YF102-LD-100 was tested on an AJ Savage in the early 1970s.

The Lycoming ALF 502/LF 507 (now Honeywell) is a geared turbofan engine produced by Lycoming Engines, AlliedSignal, and then Honeywell Aerospace.

The original YF102 was developed at the Stratford Army Engine Plant in Connecticut by adding a fan to the Lycoming T55 engine, which was used as the gas generator.[1] Six engines were built for the Northrop YA-9 prototype ground-attack aircraft. These engines were later reused in the C-8A Quiet Short-Haul Research Aircraft (QSRA).

The ALF 502 was certified in 1980 and used on the British Aerospace 146 and Bombardier Challenger 600. The derated FADEC-equipped LF 507 was used on the Avro RJ update of the BAe 146.


Honeywell ALF 502 on an early Challenger 600

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 :[2]

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


Honeywell LF 507s on an Avro RJ
ALF 502
LF 507


Type Certificate Data Sheet[2]
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 40.25 in (1,022 mm)[3]
Gear ratio 2.3:1[4]
Bypass ratio 5.7:1
Compressor 1 LP, 7-stage axial[3] + centrifugal HP 2 LP, 7-stage axial[3] + centrifugal HP
Combustor Reverse flow annular
Turbine Two-stage HP, two-stage LP
Takeoff thrust 6,700 lbf (30 kN) 6,970 lbf (31.0 kN) 7,500 lbf (33 kN) 7,000 lbf (31 kN)
Length 63.66 in (1,617 mm) 65.57 in (1,665 mm)
Height 55.5 in (1,410 mm) 54.5 in (1,380 mm)
Width 47.8 in (1,210 mm) 48.6 in (1,230 mm)
Weight [a] 1,336 lb (606 kg) 1,375 lb (624 kg) (1F: 1,385 lb (628 kg))
LP rpm 7,184 - 7,374
HP rpm 19,280 - 19,760
TSFC 0.406 lb/lbf/h (41.4 kg/kN/h)[3]
Thrust/weight 5.01 5.22 5.45 5.09

See also

Related development

Comparable engines

Geared turbofans

Related lists


  1. ^ includes essential engine accessories but excludes starter, hydraulic pump, integrated drive generator and exhaust nozzle


  1. ^ Leyes, Richard A., II; William A. Fleming (1999). The History of North American Small Gas Turbine Aircraft Engines. Reston, VA: American Institute of Aeronautics and Astronautics. ISBN 1-56347-332-1.
  2. ^ a b "Type Certificate Data Sheet E6NE" (PDF). FAA. June 7, 2002.
  3. ^ a b c d "ALF 502 Turbofan Engine -Honeywell Aerospace". November 29, 2010. Archived from the original on March 5, 2012.
  4. ^ Graham Warwick (25 August 1993). "Engine for Change". Flight International.

External links

  This article uses material from the Wikipedia page available here. It is released under the Creative Commons Attribution-Share-Alike License 3.0.



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