An F-22 Raptor successfully flew at supercruise last week on a 50/50 fuel blend of conventional petroleum-based JP-8 and biofuel derived from camelina, a weed-like plant, the Air Force said yesterday.
The March 18 flight was the capstone of a series of ground- and flight-test events conducted by members of the 411th Flight Test Squadron at Edwards AFB, Calif., in the week leading up to the flight. The F-22 is the biofuel blend flight test pathfinder for all fighter aircraft, according to the service.
The overall test objective was to evaluate biofuel blend suitability in the F-22, officials said. Testing consisted of air starts, operability and performance at different speeds and altitudes throughout the flight envelope.
The aircraft performed several maneuvers including a supercruise at 40,000 feet, reaching speeds of 1.5 Mach. Supercruise is supersonic flight without using the engine’s afterburner.
Officials said the overall flight was a success and another milestone completed for the Alternative Fuels Certification Division in support the Air Force’s 2016 acquisition goal to cost-competitively acquire 50 percent of its domestic aviation fuel requirement via alternative fuel blends in which the component is derived from domestic sources produced in a manner that is more environmentally friendly than fuels produced from conventional petroleum.
The camelina-derived synthetic fuel falls into a class of hydroprocessed blended biofuels known as hydrotreated renewable jet fuels, or HRJs. The HRJ fuel can be derived from a variety of plant oil and animal fat feedstocks.
Air Force officials in February certified the entire C-17 Globemaster fleet for unrestricted flight operations using the HRJ biofuel blend (Defense Daily, Feb. 14).