Flight trials starting in September are expected to take the final strides in a cautious lead-up to testing the first automated aerial refuelling system.

By the end of next year, US military and industry officials hope to show that two manned aircraft can fly in autonomous mode in a typical refuelling formation, safely navigating by GPS and sharing location data using a new low-latency waveform, says Jacob Hinchman, programme manager for the automated aerial refuelling programme.

Hinchman’s group includes the US Air Force, US Navy, Defense Advanced Research Projects Agency and NASA, as well as Birhle, Boeing, General Dynamics, Northrop Grumman and Syngenics. In September, the first test flight will begin by evaluating the performance of a datalink using the Rockwell Collins Tactical Targeting Networking Technology wideband, low-latency waveform tailored for airborne applications such as aerial refuelling.

A follow-up test next May, involving a Bombardier Learjet and a USAF Boeing KC-135 tanker, will mark a major test of the datalink and satellite navigation system. The Learjet will fly itself into contact position with the tanker, then remain in that formation autonomously as both aircraft continue to fly in the tanker’s normal racetrack pattern.

Finally, by late 2006, the test team will attempt a graduation flight, in which the Learjet will hold at an observation position. Then, in autonomous mode, it will move into the contact position with the tanker. After a few minutes, the tanker pilot will issue a breakaway command, which the Learjet is expected to obey.

Hinchman says the programme’s key technical challenges involve collision avoidance and improving UAV response to breakaway commands. A more practical problem is limiting cost if the entire tanker fleet needs to be retrofitted with new datalink and navigation software.

Source: Flight International