The fleet of the Air Force’s F-22 Raptors have been grounded for the past two months, that also includes newly-build Raptors from the factory. Lockeed Martin as well as US government test pilots cannot perform the necessary flight tests to allow new F-22s into service with the Air Force. The grounding of the fleet was initially caused by an F-22 crash last December in Alaska which was suspected of being caused by the F-22′s oxygen generating system failing. According to Defense News:
Technically, four aircraft have been delivered to the Air Force, but are being stored at Marietta pending the lifting of the flight restrictions. When the Air Force resumes F-22 flight operations, those aircraft will be flown to Langley Air Force Base (AFB), Va.
Two further aircraft, 4182 and 4183, have been completed, but the company and DCMA can’t do required flight testing on those jets, Stinn said. The aircraft are being stored in a near-flight-ready status, she said.
Aircraft “4182 and 4183 were scheduled to deliver in July, but they’re not in a position to do any sort of test flights, so we can’t deliver,” Stinn said. “Maybe early August, but we don’t have a definitive date.”
Aircraft 4182 and onwards, which have not undergone any of their acceptance flights, have yet to receive their final stealth coatings. The coatings are applied only after a number of flight tests have been completed, and as a result, a backlog is slowly building up.
Before the stealth coatings are applied, the aircraft fly coated only with a primer.