U.S. and Japanese fighters refuel together at Hachinohe during Keen Sword 27 hot-pit drills

U.S. Air Force and Japan Air Self-Defense Force crews refuelled F-35A and F-16 fighters side by side at Hachinohe Air Base in northern Japan from Oct. 19 to 21, as part of Exercise Keen Sword 27, according to a release from the U.S. Air Force’s 35th Fighter Wing.

The work took place on a Japan Maritime Self-Defense Force installation, which gave the two air forces a chance to practise operating from a site that neither normally uses as a home base. The 35th Fighter Wing, based at Misawa Air Base, said the aircraft involved were F-35A Lightning II jets flown by both nations and U.S. Air Force F-16 Fighting Falcons.

What hot-pit refuelling means

In a hot-pit operation an aircraft takes on fuel while its engines keep running. The 35th Fighter Wing explained that this removes the need for a full shutdown, so crews can turn an aircraft around faster and send it back into the air sooner.

The release describes the activity as practice for Agile Combat Employment, the U.S. Air Force concept of spreading fighters across several dispersed airfields rather than concentrating them on a few large bases. Sharing fuel, equipment and know-how with a partner’s installation is central to that approach.

Working across two militaries

U.S. and Japanese personnel had to adjust to differences in communication and procedures, the wing said. Chief Master Sgt. Daniel Marrufo, the 35th Fighter Wing’s plans and programs chief of wing combat plans, said: “We showed the capability that our allies are a force multiplier.”

Airman Heaven Holt, a crew chief with the 13th Aircraft Maintenance Unit, said repetition improved coordination over the three days. The teams also kept working through rain, which the wing presented as a chance to rehearse sustaining a mission in poor weather.

Part of a larger exercise

The U.S. Air Force describes Keen Sword 27 as a routine, biennial bilateral field training exercise with multinational participation, designed to raise readiness and interoperability between the U.S. military and Japan’s Self-Defense Forces. Geopolitiki has followed the exercise since its opening, including the scale of the drills reported in Keen Sword 27 opens on Ishigaki with 45,000 Japanese and 11,000 U.S. personnel and seven partner nations.

The 35th Fighter Wing said the refuelling training showed how shared resources, established relationships and practical experience can improve bilateral coordination. In the release’s words, that supports the readiness of both forces to defend Japan and contributes to credible deterrence in the Indo-Pacific. No further events at Hachinohe were announced in the release.