Built by Lockheed Martin, the F-22A Raptor is described not only as an air superiority fighter, but an air dominance fighter. Its low-observable, or 'stealth', characteristics and an advanced sensor suite are intended to ensure that air-to-air threats can be dealt with before the Raptor is even detected by hostile radars; meanwhile, the agility afforded by the twin thrust-vectoring Pratt & Whitney F119-PW-100 engines makes it a formidable opponent in air combat. The F-22 is able to 'supercruise', meaning it can sustain supersonic speeds in level flight without the use of afterburner. It is also an impressive air-to-ground strike platform, and was indeed employed in this role for its combat debut over Syria in September 2014. The US Air Force, the F-22's sole user, received 187 production examples. Operational units at Joint Base Langley-Eustis in Virginia, Tyndall Air Force Base in Florida, Elmendorf AFB in Alaska, and Hickam AFB in Hawaii fly the type