ORLANDO, Fla. — The Air Mobility Command chief has an ambitious vision for the Air Force's aerial refueling fleet that ranges from increasing the survivability of the 60-year old KC-135 to starting development on a next-generation penetrating tanker.

Once AMC's tanker capabilities-based assessment wraps up this summer, the command will know more about how it wants to pursue KC-Z, a leap-ahead development that will incorporate technologies for minimizing the aircraft's visibility to radar and infrared sensors, said Gen. Carlton Everhart.

"I'm looking for a platform that is going to give me persistence in the airspace," he told reporters March 2 at the Air Force Association's air warfare symposium. "I'm looking at a platform that is going to be able to change the waveform signature."

Industry isn’t patiently waiting by for the results of the assessment to start formulating KC-Z concepts. Lockheed Martin last year told Aviation Weekthat its design could include a blended wing body and short takeoff capabilities.

For Boeing’s Phantom Works, the KC-Z is still a thought experiment, as the aerospace company remains focused on ironing out the kinks in the KC-46A program. But Stu Voboril, the group’s capture director, told Defense News in February that its offering could hinge on a blended wing body aircraft, perhaps shaped like the X-48 unmanned demonstrator built for NASA.

"We've flown various different scaled sizes of BWB. We've done an insane amount of work around that. So now we're kind of looking at that like, okay, if that [KC-Z] is something in the future, way out in the future, that's probably a starting point," he said. "My guess is our competitors are probably thinking the same kind of thing."

Voboril acknowledged that Boeing hasn’t been particularly vocal about BWB lately, but Phantom Works continues to advance the technology. Last September, the company took a 6 percent scale model with a 13-foot wingspan to NASA’s Langley Research Center for wind tunnel testing. It eventually wants to fly a manned demonstrator.

"I think what's cool about what will eventually be KC-Z someday is not only just the platform, but also how is it going to interact with the other assets that are out there," Voboril said. "Communications and autonomy are going to be a really cool thing to look at there. If you were to open the mind up of a Phantom Works person right now, that's the kind of stuff we're thinking about."

A More Survivable Tanker Fleet

Although Air Mobility Command has been focusing on KC-Z as the next big technological leap, Everhart sees it as imperative that all his aerial refueling assets become more survivable. As the threat environment becomes more complex, AMC believes it will need tankers that can move with combat aircraft into contested airspace.

Brig. Gen. Ty Thomas, director of AMC’s strategic plans, requirements and programs, suggested that the command could adopt a "layered approach" with different levels of survivability populated among the different tanker models.

"It starts with situational awareness for the tanker crew," Thomas said. "Very little of that is on the KC-135 right now. We need to do something about that. We have ideas."

The KC-135 is undergoing a range of updates that will help bring the 60-year old workhorse into the 21st century. As part of the the "Block 45" effort, the service is refreshing the KC-135’s avionics and installing a new glass cockpit, Everhart said. The aircraft is also getting new equipment to meet the Federal Aviation Administration’s 2020 mandate.

New survivability modifications for the KC-135 could occur sometime after that. Thomas is currently assessing which technologies should make it into the next block upgrade, Everhart said.

Other survivability upgrades that could be integrated into the existing tanker fleet — which includes KC-135s, KC-10s and new Boeing KC-46As, which are just beginning procurement — include countermeasures against radio frequency threats and self-defense systems, Thomas said.

"Then, maybe a layer of signature management ... that we could probably have our first opportunity to do with KC-Z," he said.

The Air Force is currently weighing whether to buy a KC-Y between the ongoing procurement of KC-46As, which spans until 2028, and KC-Z, which could begin as early as 2035. Also under consideration is whether to pursue a clean-sheet KC-Y aircraft or buy modified KC-46As as an incremental step.

With so much in flux, it goes without saying that KC-Y requirements are also still in the air, but Thomas expressed some appetite to start incorporating signature-management technologies as part of that aircraft.

"If I could inject that into KC-Y, it would be an example of an added capability that we could put on that we don't currently have," he said.

Valerie Insinna is Defense News' air warfare reporter. She previously worked the Navy/congressional beats for Defense Daily, which followed almost three years as a staff writer for National Defense Magazine. Prior to that, she worked as an editorial assistant for the Tokyo Shimbun’s Washington bureau.

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