Lycoming T55

T55
T55-GA-714A turboshaft engine on a CH-47 Chinook
Type	Turboshaft
National origin	United States
Manufacturer	Lycoming Engines Honeywell Aerospace
First run	1950s
Major applications	CH-47 Chinook Bell 309 Piper PA-48 Enforcer
Number built	4,200+
Developed from	Lycoming T53
Developed into	Lycoming/Vericor TF40

The Lycoming T55 (Company designation Lycoming LTC-4) is a turboshaft engine used on American helicopters and fixed-wing aircraft (in turboprop form), since the 1950s. It 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. The T55 also serves as the core of the Lycoming ALF 502 turbofan. Since the T55 was first developed, progressive increases in airflow, overall pressure ratio and turbine inlet temperature have more than tripled the power output of the engine.^[1][2][3]

Variants

LTC4A-1

1,651 eshp (1,232kW)

LTC4B-8D

2,970 shp (2,216 kW)

LTC4B-12

4,600 shp (3,432 kW)

T5508D

2,930 shp (2,186 kW):Commercial version of the LTC4-8D

AL5512

4,200 shp (3,133 kW)

T55-L-5

2,200 shp (1,641 kW)

T55-L-7

2,650 shp (1,977 kW)

T55-L-9

2,595 eshp (1,936 kW)

T55-L-11

3,750 shp ( 2,798 kW)

T55-L-712

3,750 shp ( 2,798 kW)

T55-L-714

4,110 shp (3,066 kW)

T55-L-714A

4,867 shp (3,631 kW)

T55-GA-715

6,500 shp (4,849 kW):variable vane control : under development.

Applications

• Bell 309
• Boeing CH-47 Chinook
• Boeing Chinook (UK variants)
• Boeing Model 360
• Boeing RC-135- One T55 was fitted to the RC-135E derivative to provide power to the aircraft's phased array radar.
• Curtiss-Wright X-19
• North American YAT-28E Trojan
• Piper PA-48 Enforcer
• H1 Unlimited hydroplane

Specifications (T55-L-714A)

General characteristics

• Type: Turboshaft
• Length: 1,196.3 mm (47.1 inches)
• Diameter: 615.9 mm (24.3 inches)
• Dry weight: 377kg (831 lbs)

Components

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

Performance

• Maximum power output: 4,867 shp (3,631 kW)
• Overall pressure ratio: 9.32^[4]
• Turbine inlet temperature: 815 °C (power turbine inlet temperature)
• Power-to-weight ratio: (4,867 shp / 831 lbs) ~ 5.8568:1 shp/lb

See also

Comparable engines

• Allison T56
• Bristol Proteus
• Napier Eland
• Rolls-Royce Tyne

Related lists

• List of aircraft engines

References

1. https://www.flightglobal.com/pdfarchive/view/1957/1957%20-%200430.html?search=T55
2. https://www.flightglobal.com/pdfarchive/view/1959/1959%20-%200813.html?search=T55
3. https://www.flightglobal.com/pdfarchive/view/1996/1996%20-%202830.html?search=T55-L-714A
4. "CH-47D Power Plants (714) (AQC/IPC/MOI/FEIC)" (PDF).

• Gunston, Bill (2006). World Encyclopedia of Aero Engines, 5th Edition. Phoenix Mill, Gloucestershire, England, UK: Sutton Publishing Limited. p. 132. ISBN 0-7509-4479-X.

External links

• Honeywell T55 page