A Northrop Grumman X-47B unmanned aircraft has become the first drone in the history to perform autonomous aerial refuelling.
The X-47B, the first drone to have demonstrated autonomous landing and take-off from an aircraft carrier in 2013, received about 1,900kg of fuel from an Omega K-707 tanker jet during the latest test.
The experiment took place on Wednesday off the coast of Maryland and Virginia, the USA.
"We are very pleased with the outcome of this first round of probe and drogue flights with the X-47B," said Pablo Gonzalez, a program manager at Northrop Grumman Aerospace Systems. "The AAR (air-to-air refuelling) system and X-47B both performed as expected. While we would certainly benefit from additional probe and drogue flight testing, we have reached a tipping point at which AAR is now feasible."
During the demonstration, the aircraft flew in a close formation with the Omega K-707 tanker, performing a rendezvous. Upon receiving clearance from the tanker crew, the aircraft took a position behind the tanker and engaged the drogue. After completing the refuelling, the drone autonomously disengaged and returned to the base.
"AAR testing with the X-47B helps solidify the concept that future unmanned aircraft can perform standard missions like aerial refuelling and operate seamlessly with manned aircraft as part of the Carrier Air Wing," said Capt. Beau Duarte, the Navy's Unmanned Carrier Aviation program manager.
Northrop Grumman has been developing the AAR technology for the US Navy and Air Force for about ten years. Its system combines GPS navigation with infrared imaging, allowing for better precision. Thanks to the hybrid concept, the X-47B’s navigational system is also immune against GPS disruption.
Part of the Unmanned Combat Air System Demonstrator programme (UCAS-D), the system underwent the first round of in-flight testing using a manned Learjet instead of the actual drone in 2012.
According to Northrop Grumman the demonstrations are paving the way for increased autonomy of both manned and unmanned aircraft, potentially reducing operational costs.
The successful demonstration was performed while the US Navy continues to debate the objectives of its broader unmanned carrier aviation programme. The programme has been on hold for some time, awaiting a decision about the type of missions the planes should be able to carry out in the future.
"What we accomplished today demonstrates a significant, groundbreaking step forward for the Navy," Captain Beau Duarte said.
“The ability to autonomously transfer and receive fuel in flight will increase the range and flexibility of future unmanned aircraft platforms, ultimately extending carrier power projection."