Just two years after the U.S. Air Force’s F-22 stealth fighter made its combat debut in the skies above Syria, maintainers are tackling an issue with the fleet’s stealth coating that, if left untreated, could cause the radar-evading material to peel off the aircraft. Operators are beginning to see “wrinkles” in the low-observable (LO) coating that renders Lockheed Martin’s F-22 almost invisible to enemy radar.