Aerial Refueling: Look, Ma, No Hands!
Aug 14, 2007 20:06 UTCDARPA does some quietly interesting things. The latest is an autopilot that lets an aircraft perform air-air refueling – one of the most challenging routine flight tasks outside of carrier landings – without pilot intervention. While impressive on its own, such systems have special relevance because they offer the promise of unmanned fighters that can remain aloft far longer than aircraft which require human pilots. The result would be far longer strike reach and persistence, two areas that will be critical to the US Navy’s ability to keep its carrier force relevant and effective through the next 3 decades. It’s no coincidence that the J-UCAS program, which is now the Navy’s UCAS-D, was a DARPA initiative as well.
The Autonomous Airborne Refueling Demonstration program (AARD) aimed to demonstrate that unmanned aircraft can autonomously perform in-flight refueling under operational conditions. AARD uses precise inertial, GPS, and video measurements, combined with advanced guidance and control methods, to plug a refueling probe into the center of a 32-inch basket trailed behind a tanker. The test aircraft were a NASA F/A-18D Hornet with pilots on board for routine flight and safety backup, and a piloted 707-300 tanker (similar to the KC-135) from Omega Air Refueling Services. Each attempt was made from Edwards AFB in California across a range of turbulence conditions, the most challenging of which were characterized by up to 5 feet of peak-to-peak drogue motion. This approaches the limits of routine manned refueling operations – and that wasn’t all the AARD system was able to do…