New B-21 Bomber’s Aerial Refuelling Capability Ensures Global Reach Despite Much Reduced Range

The U.S. Air Force’s B-21 Raider stealth bomber has successfully tested its aerial refuelling capability with a KC-135 Stratotanker. as part of ongoing flight testing efforts. The testing of the B-21’s aerial refuelling capabilities marks a major landmark in preparing for a future win which the two types of aircraft operate closely together to provide a global capacity for sustained penetration strikes. The Air Force has not disclosed the number of B-21 aircraft participating in testing, although with production and the aircraft’s first flight having been postponed for several years, the program remains far behind schedule. 

The B-21 is notably significantly smaller than the preceding B-2 stealth bomber, meaning it carries less fuel and munitions and has a much shorter range, thus increasing its reliance on aerial refuelling for global operations. Air Force Chief of Staff General Kenneth Wilsbach recently specifically noted that the aircraft’s greater fuel efficiency could help reduce the strain on the tanker fleet, observing: “The B-21’s fuel efficiency is one of the core components of its lethality… This long-range strike bomber will reduce the demand on our tanker fleet and free up assets to support the joint force. This will provide a wider range of employment options and the deterrence our nation requires.”

Further commenting on the implications of the B-21’s aerial refuelling capabilities, commander of Air Force Global Strike Command General S. L. Davis observed: “For our bomber crews and the combatant commanders they support, this is about endurance and mission readiness… This capability ensures we can deliver penetrating long-range strike anywhere in the world, at any time. We are strengthening the capabilities of our bomber force and putting a highly effective and lethal weapon system into the hands of our warfighters.” The test occurred as the KC-135 tanker fleet has come under considerable strain in the ongoing war effort against Iran, with multiple aircraft lost in combat, while the new KC-46 tanker has continued to suffer from wide ranging issues, leading the Air Force to make clear it will not place further orders until they are addressed. 

Scheduled for service entry in the early 2030s, the B-21 is expected to replace the B-1B and B-2 bombers in service, and likely a portion of the B-52H bomber fleet, likely making it the most widely fielded single bomber type in the world. The significance of a large B-21 fleet of over 100, and very possibly over 200 aircraft, has recently been highlighted in the U.S.-Iranian conflict, as the very small size of the B-2 fleet has prevented the aircraft from being used to launch sustained strikes on Iranian targets. A B-21 fleet will not only be able to launch sustained penetration strikes due to the greater numbers of aircraft available, but will also require less maintenance, and can be based nearer to targets, where the B-2 can only be based in the continental United States.