As planners look for ways to keep fuel flowing across the Indo-Pacific battlespace, the concern is whether large tanker aircraft operating from a handful of vulnerable bases can survive the opening days of a conflict.
The worry is not merely theoretical. A 2023 Congressional Research Service report examining US military operations in the Indo-Pacific highlighted the challenge of sustaining air operations across a vast ocean theater where key bases and airfields would undoubtedly come under missile attack at the beginning of a battle. The report pointed to the importance of dispersing forces across a wider network of airfields to complicate enemy targeting and preserve operational flexibility. Similar conclusions have emerged repeatedly from Pentagon wargames and analyses, which have highlighted the risks associated with concentrating high-value aircraft at a small number of major installations.
For tankers, that challenge may be especially acute. The Air Force’s refueling fleet consists primarily of hundreds of KC-135 Stratotankers and KC-46 Pegasus aircraft. Both are large platforms that generally require long runways and substantial support infrastructure, limiting the number of locations from which they can operate. Should major hubs such as Andersen Air Force Base on Guam and/or Kadena Air Base on Okinawa in Japan be damaged or rendered temporarily unusable, tanker operations could be pushed hundreds or even thousands of miles farther from the fight, reducing efficiency and increasing operational risk.
This strategy of dispersing forces is not new. The Air Force’s Agile Combat Employment (ACE) concept is built around moving aircraft, crews, fuel, and supplies across a network of smaller operating locations rather than concentrating combat power at a few large bases. However, ACE hasn’t typically been applied to refueling operations because those big tankers are limited to certain airfields.
“The Air Force has been talking about Agile Combat Employment for years,” said Pete Castor, a retired USAF Colonel and director of business development and sales for Embraer Defense & Security. “They just haven’t really leveraged it for tankers the way they could.”
This is where Embraer’s KC-390 Millennium multimission tanker/transport aircraft comes in. Not meant to replace the Air Force’s KC-135s and -46s, company officials contend that future conflicts may require a more distributed refueling force, one capable of operating from a much larger number of airfields. The argument is rooted less in aircraft performance than geography. In a Pacific conflict, the ability to operate from a greater number of runways may prove as important as the amount of fuel a tanker can carry.
A tanker that’s not a commercial-airliner derivative
An Embraer analysis of Pacific airfields shows there are significantly more locations capable of supporting aircraft in the KC-390’s class than today’s larger strategic tankers. These include a number of military facilities in the Philippines.
Stationing refueling assets around the Indo-Pacific at smaller airfields aligns closely with ACE doctrine. Instead of concentrating refueling assets at a handful of major bases, tankers could disperse across a wider network of airfields before hostilities begin, reducing the risk that a single strike could disrupt refueling operations.
“The best way to protect an asset is by making its destruction strategically irrelevant,” said Marc Ayala, Embraer’s vice president for defense sales in North America, noting the importance of having various operating options so that taking out one base does not cripple the mission.
Unlike many tanker programs, the KC-390 did not begin life as a commercial airliner later modified for military service. That means the aircraft was purposely designed to operate from austere or damaged runways with its rugged landing gear, high ground clearance, and engines mounted to avoid foreign object debris.
“It’s already a refueling tanker and was designed from the beginning that way,” Ayala said.
That distinction has become increasingly important as Embraer works with Northrop Grumman to develop an autonomous boom refueling capability tailored to US Air Force requirements. While the KC-390 already performs aerial refueling using probe-and-drogue systems, the boom remains the preferred method for much of the Air Force fleet. The partnership combines the KC-390’s existing tanker architecture with Northrop Grumman’s engineering expertise and deep understanding of Air Force requirements.
The tanker-basing discussion may be driving current interest in the aircraft, but it is only part of the KC-390 story.
The platform was designed from the outset as a multi-mission aircraft capable of switching between airlift, refueling, medevac, firefighting, and special operations missions in a matter of hours. As mentioned, every aircraft is built for aerial refueling, allowing operators to configure the aircraft according to mission requirements, with a boom capability coming soon.
The aircraft’s cargo system was also built to give loadmasters flexibility. It can transport helicopters like the Black Hawk without removing its rotor heads, while air-and-missile-defense systems like the M142 HIMARS (High Mobility Artillery Rocket System) can easily roll on and off. Loadmasters will also appreciate the KC-390s external wheel wells and extensive tie-down options that maximize cargo space while simplifying loading.
For Embraer, those features support a broader point: the military should avoid designing exclusively for the conflict it expects to fight next. That philosophy shaped a recent 70-day demonstration tour that took the aircraft through 11 countries and a range of operating environments.
“We’ve done everything from the Arctic to the desert to the jungle,” Castor said.
The company argues that future mobility aircraft must be prepared for more than a single Pacific scenario. The same aircraft that can be dispersed across Pacific islands today could find itself supporting NATO operations or humanitarian relief missions after a natural disaster tomorrow.
That versatility has resonated with customers. Since entering service in 2019, the KC-390 has been selected by 11 nations, including multiple NATO members as well as South Korea and, most recently, the United Arab Emirates (UAE).
Castor, who previously managed foreign military sales programs while serving at the US embassy in Abu Dhabi, views the UAE selection as particularly significant.
“They’re not just great partners,” he said. “They’re true operators of the capabilities they buy.”
The expanding customer base also reflects confidence in the aircraft’s operational maturity. Brazil, Portugal, Hungary, the Netherlands, Austria, Sweden, South Korea, and the UAE represent a growing list of operators seeking modern airlift and refueling capabilities without the size and operating costs associated with larger strategic platforms.
For the Air Force, the debate over future tankers is likely to continue. The service still operates hundreds of KC-135s, some approaching 70 years of age, while KC-46 production is planned to continue through the early 2030s.
However, as planners increasingly focus on contested logistics, the question is no longer simply how much fuel a tanker can carry. It is whether that tanker can get close enough to the fight to matter.
