The U.S. Air Force conducted its first aerial refueling of fighter aircraft by a commercial tanker on Nov. 6.

The commercial refueling of F-16 Fighting Falcons from Osan Air Base in South Korea took place as part of the Commando Sling 23 joint exercise conducted in Singapore. The bilateral training event with the Republic of Singapore Air Force is sponsored by Pacific Air Forces and is intended to improve how the island nation operates with the United States.

This aerial refueling marked a major step forward for the U.S. Air Force’s efforts to broaden this capability. The service has considered augmenting its refueling operations with commercial tankers for several years. Earlier this year, a commercial tanker refueled an E-3 Sentry and an RC-135 Rivet Joint during an Air Combat Command exercise, the service said in a Nov. 9 release.

This month’s refueling during Commando Sling was carried out by a KDC-10 aircraft, the service said, and photographs showed the tanker bore the markings of Omega Air Refueling. The Virginia-based company, which formed in 2004, has been a prime contractor to the U.S. Navy for commercial refueling services since 2007. It has also supported the air forces of U.S. allies such as Australia and NATO nations.

Lt. Col. Curtis Holtman, the air mobility operations chief for Pacific Air Forces, said this refueling served as a “proof of concept” to show a commercial tanker can gas up the Air Force’s fighters during exercises and training, while keeping its own tankers available for real-world operations.

“If we can use commercial air refueling to cover the point A to point B movements for exercise participation across unit readiness training, then it frees up our warfighter tanker fleet to be ready to respond for emerging contingency requirements,” Holtman said. “This is another mechanism that we can leverage to increase our warfighter readiness.”

Photographs showed at least four F-16 jets from Osan’s 36th Fighter Squadron flying alongside the Omega tanker on their way to Singapore. The KDC-10 can carry up to 247,000 pounds of fuel to gas up other aircraft.

Holtman said this tanker carried more than 40 passengers and four pallet positions worth of cargo to show how it can also execute airlift missions. The KDC-10 can carry up to 100,000 pounds of freight or passengers.

Holtman said commercial tankers are expected to also refuel F-15C Eagle and F-22 Raptor fighters by the time the exercise ends.