Northrop Grumman (booth 3639) has flown two RQ-4 Advanced Concept Technology Demonstration (ACTD) Global Hawks in formation under its KQ-X programme to develop the concept of air-to-air refuelling for high-altitude long-endurance (HALE) UAVs.
One of the aircraft in the exercise was equipped with a belly-mounted refueling system.
The two aircraft have yet to make dry contacts or exchange fuel, however.
The Global Hawks flew in formation during the test but did not make contact
"This programme is designed to demonstrate air-to-air refuelling of high-altitude long-endurance UAVs," said Walt Kreitler, HALE Systems director of business development at Northrop Grumman. "This is a very complex mission."
Under a $33 million deal in 2010 with the Defense Advanced Research Projects Agency (DARPA), Northrop agreed to demonstrate refuelling with a pair of Global Hawks the company shares with NASA.
Although air-to-air refuelling was not originally envisaged as a requirement for HALE UAVs such as Global Hawk, Kreitler says it offers a number of benefits.
A Global Hawk with a particularly heavy payload, for example, would be able to take off with less fuel, and be subsequently refuelled in the air. In addition, a Global Hawk with a unique sensor package would be able to stay on station longer if equipped to receive fuel from another platform.
Kreitler also touched on other elements of the Global Hawk programme. The first flight of the MQ-4C Broad Area Maritime Surveillance (BAMS) aircraft is still scheduled for the end of 2012, with the second aircraft very close to completing production.