Aerial refueling has always been risky business. Tankers fly through the sky, loaded to the gills with flammable fuels while dragging long hoses or booms behind them as jets chase after them like hungry mosquitos.
But if that's risky, the first aerial refueling was straight-up crazy. Wesley Mays, a famous daredevil of the late-1910s and early-1920s, climbed from one biplane onto another with a 5-gallon jug of fuel strapped to his back.
Three men worked together to pull off the stunt. Mays, the daredevil, was joined by two pilots, Frank Hawks and Earl Daugherty. Mays rode along with his gas can in the plane piloted by Hawks. Then, he climbed out of Hawks' passenger seat and walked onto the right wing tip.
From there, he waited for Daugherty to bring his wingtip in range and grabbed it. Mays lifted himself onto the wing and worked his way between the planes' wings and into the cockpit. He poured the gas into the engine and strapped himself into his waiting seat, sealing his place in history.
The Army Air Corps got in on the aerial refueling action 2 years later in Jul. 1923, but they needed a way to transfer much more than 5-gallons at a time. So they opted to use a tanker aircraft, a hose, and a receiving aircraft. First Lt. Virgil Hines flew a DH-4B outfitted as the tanker ahead of 1st Lt. Frank W. Seifert's DH-4B receiver. Hines dangled the hose behind and beneath his aircraft where Seifert could reach it.
The fuel was transported without incident, but engine trouble in Seifert's plane prevented the duo from achieving a planned endurance record. Still, they developed techniques that allowed another Air Corps team to set the record with a 37-hour, 25-minute flight in Aug. 1923.
Today, aerial refuelings are usually conducted by specially designed aircraft, though modified fighters and attack jets such as the F/A-18 have been pressed into service when needed. The Navy has even looked at using its unmanned X-47B as an automated tanker, but the two aircraft sit in hangars and have not yet been modified for the test missions.