The Air Force and Northrop Grumman [NOC] have broken ground on a new B-21 Raider final assembly line in Palmdale, Calif., putting a previously announced effort to accelerate bomber production into construction. The new assembly line at Air Force Plant 42 is part of over a million square feet of planned facilities expected to increase annual B-21 production capacity by 25%, according to the service. The groundbreaking took place Sept. 29 and was publicized by Air Force officials Oct. 2.…