With an eye toward joint operations and cooperating with foreign allies, O’Banion also told Aviation Week that Lockheed Martin was exploring ways to hybridize the actual aerial refueling equipment on any future tanker to allow a single system to provide fuel regardless of the configuration of the receiving aircraft. At present, the Air Force primarily uses the “boom” method of aerial refueling, which involves the tanker sticking a probe into another aircraft.
The U.S. Navy and Marine Corps, as well as many of American’s foreign partners, favor the “probe-and-drogue” system, which is also common for helicopters and tilt-rotors, where the receiving aircraft has a probe that the pilot guides into a basket on the end of a fuel link trailing behind the tanker. A tanker with some sort of common system would be able to eliminate the extra weight and bulk of having to carry, or at least being able to carry, the equipment necessary to support both refueling methods.
But Lockheed Martin is also prepared for the Air Force to go in an entirely different direction with regards to aerial refueling. This could involve a distributed tanking scenario in which KC-46As operating outside the range of enemy air defenses dispense fuel into stealthy KC-Zs, which then fly back into high-risk areas to refuel other aircraft, according to Aviation Week.
The Skunk Works representative at the Air Force Association conference told The War Zone that the company was already exploring the possibility of using larger numbers of smaller unmanned aircraft, similar in size and configuration to its MQ-25 proposal, to perform the tanking mission in high-risk areas. This distributed model could also force a major conventional opponent, such as Russia or China, to devote more resources to hunt down all of the smaller tankers and make it more difficult for them to locate them in the first place.
“They’re [the Chinese] trying to find out where are there integrating nodes in our force structure that they can attack, whether it’s the overhead [satellites], or [E-3] AWACS [Airborne Warning and Control Systems] or [E-8C] JSTARS [Joint Surveillance Target Attack Radar Systems] or tankers,” O’Banion explained to Aviation Week. “One of the easiest ways to defeat that strategy is dispersement, so if I can disperse the fuel … it’s harder to defeat the ability to fuel my assets and stay in the fight.”
With all this in mind, the Air Force might eventually settle on a multi-part KC-Z concept that includes both larger, stealthy manned, or even pilot-optional, aerial refuelers and smaller tanker drones. These planes would then likely work together with existing, non-stealthy designs.
The Air Force already uses “stacked” tanking concepts, especially during special operations missions, with larger KC-135s and KC-10s refueling smaller C-130-based tankers, which then link up with tilt-rotors, helicopters, or other smaller aircraft. Lockheed Martin’s concept art notably shows its Advanced Tanker refueling an HC-130J Combat King II rescue aircraft and tanker, which typically work with HH-60G Pave Hawk rescue helicopters.
How the Air Force plans to perform combat search and rescue in denied areas is another area of growing concern and HC-130Js and HH-60Gs would simply not be able to operate in highly contested environments. It isn’t hard to imagine a KC-Z tanker supporting any future stealthy rescue aircraft, though. There will be an increasing demand for low-observable transports, too.
“We wanted to make sure that we were materially communicating to [Air Mobility Command] that full range of possibilities,” Skunk Works’ O’Banion noted to Aviation Week. “And then as AMC considers which track they want to head down they’ve got a position that maximizes their level of understanding.”
Whatever design or designs the Air Force eventually decides it wants for its KC-Z program, it’s clear that the service is well aware of the increasing vulnerability of traditional tankers. With Lockheed Martin already crafting various concepts, and its competitors, especially Boeingand Northrop Grumman, almost certainly doing the same, its aerial refueling fleet looks set to transform significantly in the years to come.