Pratt and Whitney are working on a block one improvement to the F135 engine (used on the F-35 stealth fighter) which will offer between a 7% and 10% improvement in thrust, as well as between 5% and 7% better mission fuel burn, and is undergoing testing now.
Although higher thrust and better fuel burn have obvious payload, range and mission advantages, Pratt expects the main benefit to come from trading the performance for lower operating temperatures and longer time on wing. “We are planning a life-extension for the F135, like we did on the [F100] -229 with an engine enhancement package where you had a 50% improvement in life. So we have set a goal to reduce sustainment costs for the F135 by a factor of 30%. A big piece of that will be increasing the life, which means reducing the number of depot overhauls you do over the life of the engine,” says Croswell. “The real focus for the Joint Program Office and Navy is on reducing life-cycle cost,” adds Kenyon.
Pratt and Whitney is nearing completion of the extensive F135 system development and demonstration (SDD) program for the F-35 Joint Strike Fighter engine. They are revealing new details of a proposed upgrade that could cut fuel burn by as much as 7% on aircraft entering service by the early 2020s. The upgrade package builds on a fuel-burn reduction technology effort driven by the U.S. Navy and an improved compressor developed by Pratt.
The improved design is focused on changes to the aerodynamics of the six integrated bladed rotors that form the high-pressure compressor module; it “takes advantage of the advances in aero design capability that have happened since the start of the F135 program,” Kenyon says
It is a drop in replacement engine during depot visits
SOURCES- Aviation Week, Pratt And Whitney