A series of flight tests have been successfully performed by the US Navy and Northrop Gunman in order to validate technology that has the potential to increase the flight duration and operating range of future unmanned aircraft.
The flight tests in St Augustine reached completion on Jan 21 and validated the features of the software and hardware that will assist in demonstration of autonomous aerial refueling (AAR) by the unmanned aircraft.
Northrop Grumman/Navy team employed a K707 tanker from Omega Air Refueling and Calspan’s Variable Stability Learjet as the X-47B surrogate aircraft in order to conduct the AAR tests. The tests encompasses simulated flight demonstrations of both probe-and-drogue and boom and receptacle aerial refueling techniques.
For independent refueling operations, the X-47B employs the Learjet surrogate equipped with functional or real equivalents of the flight control processor, navigation systems, and vision systems. The aircraft is devoid of any refueling receptacle or refueling probe.
The Learjet/X-47B surrogate was piloted each time to a fixed position about 1nmi from the tanker. The aircraft’s control was then transferred to the X-47B's autonomous flight control processor that leveraged Learjet during the test event.
The process at the refueling event includes controlling the flight of the Learjet to fly to major positions of aerial refueling, by the mission operator or tanker operator on the ground. The positions included the pre-tanking observation point off one wing of the tanker, followed by the refueling contact position behind the tanker, concluded with the post-tanking "reform" position off the other wing of the tanker.
Source: http://www.northropgrumman.com/