Allison T56
| T56 / Model 501 | |
|---|---|
| A T56 mounted on a U.S. Air Force C-130 Hercules receives maintenance. | |
| Type | Turboprop |
| National origin | United States |
| Manufacturer | Allison Engine Company Rolls-Royce plc |
| Major applications | Convair 580 Grumman C-2 Greyhound Lockheed C-130 Hercules Lockheed L-188 Electra Lockheed P-3 Orion Northrop Grumman E-2 Hawkeye Lockheed CP-140 Aurora |
| Number built | >18,000 |
| Developed from | Allison T38 |
| Developed into | Rolls-Royce T406 |
The Allison T56 is an American single-shaft, modular design military turboprop with a 14-stage axial flow compressor driven by a four-stage turbine. It was originally developed by the Allison Engine Company for the Lockheed C-130 Hercules transport entering production in 1954. It has been a Rolls-Royce product since 1995 when Allison was acquired by Rolls-Royce. The commercial version is designated 501-D. Over 18,000 engines have been produced since 1954, logging over 200 million flying hours.