This would be a significant design difference from current tankers.
In August 2023, the Air Force selected JetZero to partner with Northrup Grumman to develop a prototype to test the BWB design. This may also play a role in the Air Force’s long-term plans for its Next-Generation Aerial-refueling System (NGAS).
Strong need for more efficient, less vulnerable tankers
In planning for future operations, the Air Force has determined a growing need for new tankers with better fuel efficiency, longer range, and increased payload capacity. A major concern for this is to support fighters and ground attack aircraft just hundreds of miles from combat zones. With current tanker models, this close-up support would leave the tankers vulnerable to attack from enemy aircraft.
The Air Force KC-135 and KC-46 Pegasus tankers flying today are modified versions of commercial passenger jets. One of the Air Force’s primary goals for a new tanker design is for it to have greater range while being more efficient and cost effective. This has led to research in blended wing body designs.
JetZero and Northrup Grumman leading blended wing design research
JetZero is leading this effort with its “Pathfinder” prototype or demonstration model. It has a wingspan of 23 feet, approximately one-eighth of the 184 feet they plan for a full-scale aircraft. The blended wing design combines the wings and fuselage into a single unit. This produces several aerodynamic advantages over traditional tube and wing aircraft.
The Pathfinder’s combined wing and wide central body make a large surface area and allows the entire aircraft to produce lift. One advantage from this is a 9.4% lift to drag ratio better than conventional models.
Blended wing aircraft more efficient than older designs
A recent study showed that this configuration will lead to a 27% reduction in fuel burn per passenger mile or a 50% reduction in fuel consumption. Another benefit of the BWB that would be effective for tankers is a lighter maximum takeoff Weight (MTOW). This partly comes from it having less surface area than conventional designs. This lighter weight produces another advantage of having the aircraft lighter weight requiring small engines, which only adds to the overall efficiency, which then increases range. Yet another advantage is that BWB aircraft are quieter.
“Blended wing body aircraft have the potential to significantly reduce fuel demand and increase global reach,” said Secretary of the Air Force Frank Kendall. “Moving forces and cargo quickly, efficiently, and over long distance is a critical capability to enable national security strategy.”
Need for new tanker designs to have low observable features
Blended wing body design features may also impact plans for the Air Force’s plans for its Next-Generation Aerial-refueling System (NGAS). However, the purpose of this program is not just to deploy more cost-effective tankers with more range. One of the most important goals for the NGAS is to be able to refuel low-observable or stealthy aircraft like the B-21 bomber and the F-35 fighter. Air Force planners want tankers to get closer to where the bombers and fighters are flying.
“To have tactical fighters that can operate effectively, you’ve got to tank them within a few hundred miles of where they’re going to operate,” said former Secretary of the US Air Force Frank Kendall. “So, we need tankers that can get into ranges where they are now threatened. Current tankers are not very effective at that. And the commercial derivative tanker, which is a traditional route to getting one, is probably not going to be effective either, although that’s not off the table yet.”
Flying refueling missions close to the forward battle area leaves tankers vulnerable to enemy aircraft. This emphasizes the need for tankers to have stealthy features.
Changes required to make blended wing aircraft less vulnerable
Some have suggested that BWB tankers, with their flying wing designs that look similar to the B-2 and B-21, might also have stealthy qualities. However, research has not proven this yet. To make the design a true low-observable aircraft, one change would be to incorporate the engines more into the interior of the airframe than on the Pathfinder.
There is widespread interest in developing BWB aircraft for commercial and military purposes. Boeing, Lockheed Martin, Airbus, and Bombardier are also working on developing BWB tanker designs for NGAS.
New fuel potential for blended wing design
Looking ahead, manufacturers are also working on different fuels systems for aircraft. One of these is to use hydrogen as a zero-carbon option. JetZero has determined that its BWB design will be able to accommodate hydrogen fuels. It expects this technology to be ready by 2030, which only makes blended wing body aircraft more promising.
Credit: avgeekery.com
