DARPA 
has completed a two-year program that the agency says demonstrated technology enabling autonomous in-flight refueling of high-flying remotely piloted aircraft. During the Autonomous High-Altitude Refueling program (previously called KQ-X), two modified RQ-4 Global Hawks completed a total of nine flight tests, according to an Oct. 5 agency release. During the final flight, a simulated refueling rendezvous, the two aircraft flew in “close formation,” with the one aircraft’s refueling probe and the second airplane’s receiver drogue less than 100 feet apart for the majority of a 2.5-hour engagement at 44,800 feet, states the release. “This demonstrated for the first time that high-altitude, long-endurance class aircraft can safely and autonomously operate under in-flight conditions,” states the release. “The goal of this demonstration was to create the expectation that future HALE aircraft will be refueled in flight,” said Jim McCormick, DARPA program manger. The AHR program concluded on Sept. 30. (See also Refueling the RPAs from Air Force Magazine’s 2012 archive.)
While U.S. defense officials have spent much of the past decade warning that China is the nation’s pacing threat and its People’s Liberation Army represents an urgent threat in the Indo-Pacific, several defense researchers are skeptical that the PLA has the human capital, the structural ability, or the political appetite…