Over Signal Hill, California, two planes lapped wings, barley six feet apart. The lower one was a Lincoln Standard, the other, a JN-4 “Jenny.” From the Jenny’s left skid, Wes May swung back and forth trying to work up onto the lower wing. Moments before he’d been on the wing of the Standard. On his back, instead of a chute, hung a chunky 50-pound can. Finally his foot hit the skid, and he slowly worked his way forward until he stood on the leading edge. Wes made his way toward the fuselage. He unstrapped the can and with one hand clutching the plane, Wes tipped the can at the gas tank. Most of the fuel poured into the slipstream, but some actually got into the tank.

For May and Earl Daugherty, the Jenny pilot, their feat of November 12, 1921, was a great step into the future: something to do with men flying cross country in less than a day; of going around the world nonstop. It was crude, but it was the world’s first air-to-air refueling.

Barnstormers like Daugherty and May, who had learned to fly during the war, provided popular aerial amusement during the early 1920s. But beyond the thrills, many of these flyers barnstormed with a purpose. When Daugherty and May proved that gasoline could be transferred air-to-air, it was the beginning of a new engineering concept that would keep planes aloft longer for far-reaching missions. Neither man would live to see the legacy of record-breaking nonstop flights that followed their “stunt.” But by the late 1960s, one aerial hookup was made on average every minute, 24 hours a day. Aerial refueling is one of the most vital support missions in today’s defense systems.