U.S. considers unmanned tankers to replace KC-135 and KC-46

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Air Force explores unmanned tankers to replace its ageing refuelling fleet

The MQ-25's progress has revived plans for autonomous Air Force tankers

Range remains the biggest obstacle to building an unmanned tanker today

The US Air Force is considering whether its next refueling aircraft, expected to replace the KC-135 and KC-46, could fly with no crew aboard.

The idea gained ground because the Navy's Boeing MQ-25 Stingray, an unmanned refuelling drone , flew for the first time earlier in 2026.

On Thursday, the Navy cleared the MQ-25 for low-rate production and purchased three additional units, raising its order to 14 aircraft.

Crews are not needed, but size remains unsolved

At the recent Air, Space & Cyber 2026 conference in National Harbor, Maryland, the Air Force said its future refueling aircraft might not need a crew.

“I do not believe that it has to be manned, a future air-refuelling solution…But then, how do we, the U.S. Air Force, bring that to bear in scope, scale, and range?” said Lt. Gen. Daniel Tulley, commander of Air Mobility Command

The service is still buying Boeing KC-46 Pegasus tankers, and it spent $12 million this year to study a new tanker design.

However, its proposed fiscal 2027 budget drops that funding entirely and asks for $13 million instead, labelled as money for advanced refuelling systems.

Tulley said a tanker able to cover the needed distances would be huge, and no fully autonomous aircraft of that size flies today.

The current KC-46 has a range just short of 7,400 miles and carries over about a hundred tons of fuel.

However, the autonomous MQ-25, which is driving this idea, manages roughly 500 miles and holds up to 7.5 tons, which is a small share of what the KC-46 offers.

Boeing’s aircraft can currently take off, follow programmed routes, and land on autopilot, though the Air Force does not use them autonomously.

The Air Force is probably hoping to build on this autopilot capability, aiming to turn the partial automation into full autonomy.

Merlin Labs says autonomy can begin with crews aboard

Merlin Labs, a company that builds autonomous flight systems, plans to install its autonomous pilot software on the C-130J, an aircraft similar in size to the KC-135.

The aircraft will still carry a human crew, which lets Merlin add autonomy step by step instead of jumping straight to an unmanned tanker.

“That's a way that you can start to chip away at that without actually going fully to the unmanned tanker right away,” said Matthew George, CEO of Merlin Labs.

“The goal is that the unmanned tanker is ready, and the autonomy ends up being ready at the same time.”

The company must next win certification, and it is working with the Air Force this year to get that approval.

“None of this matters unless it's certified and safe. So for us, getting certification done is important, and that's what we're working really closely with the Air Force on this year,” George said.

Merlin has not announced a date for the C-130J to carry its autonomous pilot, though the company's technology has completed a critical design review.

With no set flight date and unfinished certification, the Air Force's plan for an unmanned tanker the size of the KC-46 remains far off.

Via Defense One