An engine upgrade that could reduce fuel burn by 8% on hundreds of Lockheed Martin C-130Hs will soon enter flight test, Rolls-Royce says.

The engine maker has completed development of the series 3.5 upgrade of the T56 engine, which powers the C-130 and Lockheed P-3 Orion.

The flight test programme should lead to certification in advance of a US Air Force decision on funding the first tranche of upgrade kits in fiscal year 2014, R-R says.

The fuel burn improvement requires no change in the overall pressure ratio or the bypass ratio of the T56 powerplant. Instead, R-R has made component improvements. For example, the material used in the turbine blades has been upgraded to burn hotter, allowing the company to eliminate the parasitic cooling requirement using bleed air from the compressor. The turbine blades have also been upgraded to three-dimensional aerodynamic designs.

R-R estimates that there are 220 C-130Hs in the USAF fleet that could be upgraded. The air force plans to continue operating the H-model Hercules until 2040, the company says.

The USAF is also considering replacing the aircraft's four-blade propeller with the eight-blade Hamilton Sundstrand NP2000.

Source: Flight International