Key point: The B-21 will be the spearhead of America's next-generation aerial penetration capabilities
On October 27, 2015, nearly thirty-four years to the day after Northrop Grumman was awarded the contract to develop the first stealth bomber, the U.S. Air Force awarded Northrop a contract for a new bomber: the B-21 Raider. While many of the details of the Raider are shrouded in mystery, we do know a few things about it, and can infer others.
The B-21 Raider bomber takes its name from both the twenty-first century and the legendary 1942 raid by Gen. James “Jimmy” Doolittle’s force of B-25 Mitchell bombers against targets in and around Tokyo, Japan. In invoking the Doolittle Raid, the Air Force is drawing attention to attack’s audacious nature, the strategic and tactical surprise, and the epic distances General Doolittle and his “raiders” flew to accomplish their mission.
A tailless, batlike aircraft, the official rendering of the B-21 Raider released by the Air Force bears a superficial resemblance to the B-2 Spirit bomber. There are important distinctions, however. The B-21 moves its engines closer to the wing root, where they occupy the juncture between wing and fuselage, whereas the B-2’s twin pairs of General Electric F118-GE-100 engines are distinctly apart from the fuselage on the wing. The Raider’s engine air intakes are angled and not serrated like those on the B-2 Spirit. The Raider also has overwing exhausts to mask the infrared signature of the four engines, unlike the B-2. (Interestingly, this is exactly how the B-2’s exhausts were depicted in an April 1988 artist’s conception of that bomber.)
The aircraft appears similar in size to the B-2 Spirit, almost certainly making it a four-engine bomber. The announcement of Pratt and Whitney in 2016 as a B-21 subcontractor narrows down the new bomber’s engines to two designs: the F-100 and the F-135. The mature F-100, which powers the F-15 Eagle series of fighters, seems a sound choice, but the Air Force may want the F-135, which powers the F-35 Joint Strike Fighter, for its growth potential and ability to lower engine costs for the F-35 fleet.