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)
The Air Force overall reduced its size by 120 aircraft in fiscal year 2021, but kept about the same number of fighter, bomber and attack aircraft, according to data supplied by the service. The F-35 fleet saw the biggest increase while the B-1B bomber fleet saw the largest decline.