Rolls-Royce and the US Air Force began flight testing for an upgraded T56 turboprop engine for the C-130H Hercules during a sortie at the Air Force Test Center at Edwards AFB, California, on 14 September 2012. The T56 Series 3.5 Engine Enhancement is expected to increase fuel savings and improve reliability. The Series 3.5, with new materials and new-design turbine vanes blades and vanes, will also improve performance in hot and high operating conditions. This upgrade has already demonstrated greater than eight percent fuel burn improvement in ground tests. The engine improvements can be installed as part of a conventional engine overhaul and do not require any aircraft or engine control system modifications.
