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Lycoming PLF1A-2 Turbofan Engine


Display Status:

This object is on display in the Boeing Aviation Hangar room at Steven F. Udvar-Hazy Center in Chantilly, VA.

Lycoming PLF1A-2 Turbofan Engine

Collection Item Summary:

The PLF1A-2 was the first high bypass (6:1 bypass ratio) fan engine run in North America. Lycoming's high bypass fan engine concept evolved from a 1950s series of conceptual studies directed to better compete with turboprops. By 1962, prototype design had begun utilizing the Lycoming T55-L-7 turboshaft as the engine core. Considerable feasibility tests were conducted in both private and government facilities in 1964 and 1965, and a window of opportunity opened with the early-1970s Air Force AX competition.

Derived from the PLF1A, Lycoming's YF102-LD-100 engine for the Northrop A-9 close combat aircraft performed very well during aircraft testing, although the Fairchild A-10 was selected in the fly-off competition. Lycoming later redirected efforts toward the commercial market with the ALF502D version of the YF102, which was successfully applied to the Canadair Challenger CL600 executive jet and British Aerospace BAe 146 commercial jetliner.

This PLF1A-2 was one of two prototype development engines, but never flew.

Collection Item Long Description:

Data Source

National Air and Space Museum


Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum

Credit Line

Gift of Textron Lycoming.


Length 168.3 cm (66.277 in.), Diameter 103.3 cm (40.68 in.)

Country of Origin

United States of America



Physical Description

  • Type: Turbofan
  • Thrust: 19,224 N (4,320 lb) at 19,280 rpm
  • Fan: Bypass ratio 6:1, single stage
  • Compressor: Single-stage fan, 7-stage axial, 1-stage centrifugal
  • Combustor: Annular reverse flow
  • Turbine: Single-stage core, 2-stage free power turbine driving fan
  • Weight: 374 kg (825 lb)


PROPULSION-Turbines (Jet)

Inventory Number


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