Can you refuel an airplane in flight?

Most military aircraft, heliocopters and fixed-wing aircraft, are equipped and the pilots trained to allow them to be refueled in-flight. Civilian aircraft are not designed to be refueled in-flight. == In-flight refueling was a concept that dates back to the earlies days of aviation. The weight of the aircraft was so critical, this sometimes limited the fuel and therefore the range of the aircraft. On November 21, 1921, a unique method was tried. Frank Hawks flew his Lincoln Standard biplane over Long Beach, California. Wesley May, a barnstorming wing walker, crawled up onto its top wing. With a five-gallon can of gasoline strapped to his back, May started walking toward the edge of the right wing. Meanwhile, Earl Daugherty, perhaps America’s greatest stunt pilot, eased his Curtiss Jenny just above the Lincoln. When Daugherty got his lower left wing within range, May reached up and grabbed a loop on its lower edge. Then Daugherty eased away, with May and his gas can hanging below. May climbed up onto the lower wing and eventually poured the gasoline into Daugherty’s tank. November 18, 1923, some aviators attempted refueling over Kelly Field in San Antonio, Texas, as part of a carnival exhibition. The hose from the tanker caught in the propeller of the receiver, and the tanker crashed. And in July 1935 a pair of brothers, Fred and Algene Key, of Mississippi, set a record that still stands by keeping "Ole Miss", a Curtiss Robin J-1, in the air for 653 hours and 34 minutes, more than 27 days. During the 1970's, the Shah of Iran was head of one of the most weathiest oil-producing countries. He contracted with several US companies and especially aviation companies for business. When the US Air Force was designing a Boeing 747-200 for the E-4 Airborne Command Post (military predecessor of the current Air Force One), he asked if Boeing could incorporate the refueling receptable of the E-4 into his civilian Boeing 747s. A gallon of aviation fuel weighs about six and a half pounds, which is enough to fly 1909 Wright Signal Corps airplane for 16 minutes OR a World War II B-24 for 18 seconds, OR a modern F-15 fighter for about 6 seconds.