Lycoming T55

Lycoming_T55_EngineThe Lycoming T55 was designed at the Lycoming Turbine Engine Division in Stratford, Connecticut as a scaled-up version of the smaller Lycoming T53. Both engines are now produced by Honeywell Aerospace.

In 1955, the twin rotor helicopter was in development and Lycoming developed the T55 engine to meet the needs of this revolutionary helicopter design. The T55-L1 engine was originally developed for the DeHavilland Caribou, with its common core evolving over the decades to the T55-L5 for the CH-47A “Chinook” helicopter.

The innovative modular design of the T55’s core allowed it to be developed into the ALF 503, a turbofan engine used on the BAe146 regional airliner.

In the meantime, the T55 engine has grown with the Chinook helicopter since the first engine was delivered in 1961. A continuing infusion of Honeywell technology has more than tripled the horsepower of the T55 since its inception.

AVCO-MIT_0000_Layer 9

Original sales brochure for the T55 from the Connecticut Air & Space Center Archive.

Today, all U.S. Army Chinooks operating in Afghanistan, where “high and hot” capability is a must, are powered by T55-GA-714A engines. Indeed, Chinooks have taken over missions of other helicopters because of their ability to operate high in the mountains. Known as the “unsung hero of Afghanistan,” more than 5,000 military and commercial engines have been delivered, accumulating over six million flight hours.

Since its inception more than five decades ago, the T55’s robust design has permitted steady growth in performance with the latest engine technologies. This is the legacy of the high-performance turboshaft engine with a broad range of power options and continuous improvements.

General characteristics
Type: Turboshaft
Length: 47.1 inches
Diameter: 24.3 inches
Dry weight: 831 lbs

Compressor: 7-stage axial compressor and 1-stage centrifugal compressor
Turbine: 2-stage gas producer and 2-stage free power

Maximum power output: 4,867 shp
Overall pressure ratio: 9.32
Turbine inlet temperature: 815C (power turbine inlet temperature)
Power-to-weight ratio: (4,867 shp / 831 lbs) ~ 5.8568:1 shp/lb

Our museum would like at acquire an Lycoming T55  for display. Please contact if you could help us make this happen. 

Additional information provided by Honeywell 


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