Farnborough, UK—Pratt & Whitney’s F135 engine improvement program, along with the Air Force’s new Advanced Engine Technology Program, could produce up to 25 percent better fuel efficiency—hence much better range—for the F-35, Pratt’s Bennett Croswell, president of Pratt military engines, told Air Force Magazine Monday. The first block of Pratt’s in-house upgrade could be designed by 2019 and in production in 2024, he said, delivering 7-10 percent better efficiency. Block 2, incorporating lessons learned from AETP, would follow five years later, and could up the efficiency to a total 25 percent better fuel burn over the existing F135. However, Croswell said the F-35 would probably need to be modified to accept a new engine. The airframe is “basically wrapped around it,” and the fit is snug. While he said the intakes wouldn’t have to be altered, “the back end” would need to grow, “and if you do that, the exhaust nozzle” would probably have to be re-engineered as well. Croswell declined to speculate about whether AETP is meant to give GE—and competitive engine buys—another chance. The alternative F136 engine, developed by GE, was killed by Defense Secretary Robert Gates, who insisted it was unnecessary and wasteful.
U.S. Air Force F-35s and F-22s regularly deploy deep into the Pacific region from Alaska, Utah, and Hawaii. In the future, though, the head of U.S. Indo-Pacific Command would like to see the Air Force permanently station fifth-generation aircraft west of the international date line—closer to China.