Rolls-Royce has completed the first flight of a modified T56 engine, the Series 3.5, to improve fuel efficiency of the legacy examples that power the Lockheed Martin C-130 transport and P-3 maritime patrol aircraft.
The new engine makes a number of technical improvements to the existing power plant, which first entered production in 1954. The US Air Force, which is working with R-R to test the engine, flies 220 C-130Hs with four T56 engines each, many of which are slated to remain in service for decades. A portion of the US Navy's P-3 Orion fleet also uses the engine, and the service has shown interest in the Series 3.5 modification. Hundreds of additional C-130s are in civil and military use throughout the world.
There are roughly 6,000 T56s in operation, according to R-R, which purchased original manufacturer Allison in 1995.
The Series 3.5 modification adapts technology from previous civil and military programmes to older engines. The improvements include compressor and turbine blades with different airfoils, a new compressor inlet housing and new seals.
While the USAF has not committed to purchasing the engine modifications, the service has been charged with reducing fuel burn by 10% within three years. An air force analysis of the Series 3.5 modifications concluded a potential long-term reduction of $2 billion through reduced fuel burn.