The Air Force last week conducted biofuel testing with an F-22 at Edwards AFB, Calif. The Raptor flew on a half-and-half blend of hydrotreated renewable jet fuel and standard JP-8 aviation fuel. HRJ is derived from inedible herbaceous stock; in this case, it’s oil from the camelina plant. The F-22 prosecuted a battery of tests throughout its flight envelope, including cruising at Mach 1.5 in level flight at 40,000 feet. The aircraft “performed flawlessly on the biofuel blend, citing no noticeable differences from traditional JP-8,” said Jeff Braun, director of the alternative fuels certification division at Wright-Patterson AFB, Ohio. Service officials have chosen the F-22 as the pathfinder platform for certifying all fighters to use this fuel blend. Back in February, the C-17 became the first USAF aircraft cleared for unconstrained use of HRJ blends. The Air Force is embracing HRJ and other alternative fuels to decrease US dependency on foreign-sourced petroleum. (Edwards release)
Collaborative Combat Aircraft designs from Anduril and General Atomics passed their Critical Design Reviews early in November, clearing the way for detailed production efforts to get underway, the Air Force said. How future versions will be upgraded is still under discussion.