IMMEDIATE RELEASE August 9, 2007
DARPA COMPLETES AUTONOMOUS AIRBORNE REFUELING DEMONSTRATION
System Performs “Better Than a Skilled Pilot”
The Defense Advanced Research Projects Agency (DARPA) completed its Autonomous
Airborne Refueling Demonstration program this month, showing that unmanned aircraft can autonomously perform in-flight refueling under operational conditions.
These recent flights built on the first-ever fully autonomous refueling, conducted under
controlled test conditions last August. Since then, the Autonomous Airborne Refueling
Demonstration (AARD) has completed 10 additional flights.
The Autonomous Airborne Refueling Demonstration used 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.
Flights were conducted at Edwards Air Force Base, Calif., with a NASA Dryden Flight Research Center F/A-18, configured to operate as an unmanned test bed, refueling from a 707-300 tanker. A NASA pilot was on board the F/A-18 for safety purposes.
Several control techniques were tested, and the best was 100 percent effective in 18
attempted probe-and-drogue connections. Each attempt was made in level flight across a range of turbulence conditions, the most challenging of which were characterized by up to five feet of peak-to-peak drogue motion, approaching the limits of routine manned refueling operations.
The AARD system also demonstrated the ability to make contact during turns. Although
pilots routinely follow a tanker through turns while connected, they typically do not attempt to make contact in a turn. In the AARD program, fuel was routinely transferred in turns as well as during straight and level flight.
The system further demonstrated the ability to join the tanker from up to two nautical miles behind, 1,000 feet below, and 30 degrees off heading, thus providing a ready transition from the waypoint control approach used by most unmanned aircraft to a fully autonomous refueling mode. In recent flights, automatic sequencing reflected improved confidence in the system, compared to last year’s flight where pilot consent was required at specified points in the refueling maneuver.
While NASA test pilot Dick Ewers characterized some of the less mature versions of
AARD software as “flying like a second lieutenant,” he found the final configuration
demonstrated this year “better than a skilled pilot.” Ewers explained, “Skilled pilots can actually save some tricky, last second movement the basket has a habit of making, but in so doing they set themselves up for a basket strike, ripping off the basket from the hose, or sometimes breaking the probe or parts of the airplane.”
The exceptional performance ultimately achieved by the program was made possible by
two major enhancements to the AARD system. Improved video processing eliminated
troublesome dropouts, allowing the system to conduct four times as many plug attempts per flight, while advanced control algorithms proved capable of anticipating much of the overall drogue motion.
These algorithms were actually able to precisely match the drogue motion – something pilots are specifically taught to avoid. In one case, the system followed the drogue through a full three-foot cycle in the two seconds before making contact, never deviating more than four inches from the exact centerline of the drogue, all while traveling at 250 miles per hour, 18,000 feet above the Tehachapi Mountains.
Autonomous in-flight refueling is a critical enabler for affordable persistent unmanned
strike systems. It offers to revolutionize unmanned air operations and enhance the reliability, safety and range of operating conditions for in-flight refueling of manned aircraft.
Sierra Nevada Corp. led the AARD team. The 707-300 tanker was operated by Omega
Air Refueling Services.
Defense Advanced Research Projects Agency
3701 North Fairfax Drive
Arlington, VA 22203-1714
Mediawith questions, please contact Jan Walker at jan.walker[at]darpa.mil. Contractors or military organizations, contact Lieutenant Colonel Jim McCormick, (703) 509-7510, or
I for one welcome our new robot overlords
That is beyond awesome.
So, then the mission time for future UAVs -> infinity? Cool.
Unmanned carrier landings, check
Unmanned in flight refueling, check
Artificial intelligence to operate in lost link situations, in work
I'd say block 20 of the junk strike fighter (if it's ever operational at all) will probably be unmanned or optionally manned. That's if the X-47B doesn't yield a competing completely unmanned strike aircraft and make F-35 UCAVs uneccessary.
If they're turbine powered you have to add oil occasionally, or build a big ass reservoir into it. That would be about it except for repairing broken shit. The next thing will be automating the tanker too.
It wouldn't be tough at all to make a UAV tanker with probe and drogue. The flying boom would be no more difficult than what they've already done.
have a relative, ex high ranking air force, flew all the fighters before he retired..
i see the future and its all pilotless stuff flown remotely either by folks back at a close base (close to the action for really quick response time) or back in the good ole usa. he said no way... always need the pilot in the seat.. so i keeps my mouth shut.. but the future is more and more unmanned weapon systems, small teams of highly trained specialists with great mobility and skynet like support.
its obvious.. soldiers no longer line up in napoleonic formations, dress the line and march shoulder to shoulder towards the enemy lines. civil war put that method to rest and wwI confirmed its obsolescence along with cavalry charges. wwII showed coordinated air/armour blitkrieg warfare, which has been improved a bunch, and gulf war i and ii and a-stan have shown the future of semi-manned remote controlled warfare...
beyond that is viral dna altering agents and micro nukes.....
putting man in the battle is the most expensive component.. its just simple economics...
I figure it will start out as pilots leading packages of UAVs and doing a bit of the battle management.
Imagine going up against an F-22 leading three stealthy UCAVs.
This is really neat stuff.
I find this most impressive.