B-21 Stealth Bomber Update: Set to Fly Next Year? The first serial B-21s are expected to begin operations in the mid-2020s. The current target is to have at least one hundred of the B-21 Raiders in service by the early 2030s to replace the aging fleet of Air Force bombers. It has been a busy month for Air Force Gen. Timothy Ray, the head of the U.S. Air Force Global Strike Command. He took part in a very special tour, one that involved seeing the progress that is being made on the Northrop Grumman B-21 Raider. The aircraft’s first flight could still be a year away, but Gen. Ray made the rounds to check in to make sure that is still on track.