KQ-X

KQ-X
A Northrop Grumman RQ-4B similar to that to be used in the KQ-X aerial refuelling trials.

KQ-X is a $33 million DARPA program awarded to Northrop Grumman Corporation on July 1, 2010. KQ-X will investigate and develop Autonomous Aerial Refueling techniques using two NASA Global Hawk high altitude long endurance (HALE) unmanned aerial vehicles (UAV).

Northrop Grumman plans to retrofit two of the HALE UAVs so that one aircraft can pump fuel into the other while in flight via a hose-and-drogue refueling system. Several aspects of the KQ-X program are considered revolutionary: not only will the aerial refueling be autonomous, but since Global Hawks are classified as HALE UAVs, the refueling tests will occur at an altitude higher than that typically performed using manned aircraft. The test will also be the first time that HALE UAVs have been flown in formation.

Engineering work will be completed at the Northrop Grumman Unmanned Systems Development Center in Rancho Bernardo, California. Pilots from NASA, NOAA, and Northrop Grumman will fly the Global Hawks from the NASA Dryden Flight Research Center at Edwards Air Force Base, also in California. Sargent Fletcher Inc. and Sierra Nevada Corporation are major KQ-X subcontractors.

The first flight demonstrations occurred from January 11, 2012 to May 30. Milestones achieved included the lead receiver aircraft extending and retracting its aerial refueling hose several times, the trail tanker aircraft successfully demonstrating precision control in formation with manual and automated “breakaway” maneuvers for safety, the two Global Hawks successfully flying in close formation, at times as close as 30 feet away, and one aircraft flying more than 2.5 hours under autonomous formation control with the other flying within 100 ft.