After sitting atop the fighter rankings for more than a quarter-century, the F-22 Raptor is now living on borrowed time. Today, a new fighter, being developed in the Air Force’s Next Generation Air Dominance Program, promises to usher in yet another revolution in air combat technology, as today’s F-22s fly off into the sunset. But with at least a decade before the NGAD fleet will reach full strength, America is investing billions into keeping the F-22 as capable — and deadly – as ever.