DARPA RQ-4A Air-to-Air Refueling Program Analysis
Air-to-air refueling (AAR) has been commonplace in manned aviation for more than six decades. Today, remotely piloted vehicles fly hundreds, and sometimes thousands of miles from their launch bases to for intelligence, surveillance, and reconnaissance missions. The inability to refuel in-flight limits time on station and increases the number of aircraft required to surveil a given target location. DARPA's KQ-X program, initiated in 2010, was designed to prove the technologies required to refuel UAVs in-flight. DARPA has released videos of the close-proximity test flight of two modified RQ-4A Global Hawk unmanned aerial vehicles. The final test flight last May demonstrated the ability of close formation flight for most of a 2.5-hour engagement at 44,800 feet. Although the UAVs did not actually pass fuel, post-flight analysis indicated that 60% of attempts would achieve contact between the "Navy style"...