The Automated Aerial Refueling (AAR) system maneuvers
a Calspan Inc. Learjet, equipped to fly as a UAV, into
a refueling position behind a USAF KC-135R.
12/4/2007 - ST. LOUIS -- Can an unmanned air vehicle be made
smart enough to autonomously rendezvous with a tanker aircraft
and refuel? Based on recently concluded flight tests by the
U.S. Air Force Research Laboratory and Boeing [NYSE: BA], it
"By adding an automated aerial refueling capability to
UAVs, we can significantly increase their combat radius and
mission times while reducing their forward staging needs and
response times," said David Riley, Boeing Phantom Works
program manager for the Automated Aerial Refueling (AAR) program.
The goal of the government-industry AAR program is to develop
and demonstrate systems that will enable UAVs to safely approach
and maneuver around tanker aircraft so they can successfully
perform boom and receptacle refueling operations. The systems
-- including a flight control computer and control laws developed
by Boeing Phantom Works -- are demonstrated using a Calspan
Learjet specially equipped to fly autonomously as a UAV.
During a recent flight test, the AAR system autonomously guided
the Learjet "UAV" up to a Boeing KC-135R tanker and
successfully maneuvered it among seven air refueling positions
behind the tanker -- contact, pre-contact, left and right inboard
observation, left and right outboard observation, and break
away. The system controlled the Learjet for more than 1 hour
and 40 minutes and held the aircraft in the critical contact
position for 20 minutes.
While a pilot flies the Learjet to and from the vicinity of
the tanker and stands by to take over if necessary, he does
not otherwise control the aircraft during the refueling maneuvering
portion of the experiment.
"These tests show that we are making great advancements
in system integrity, continuity and availability through improved
relative navigation algorithms, control laws and hardware,"
Riley said. "They also show we are making great strides
toward transitioning AAR technology into production."
Plans call for a follow-on Phase II program that will include
autonomous multi-ship operations and delivery of fuel to the
The AAR team includes a diverse set of government and contractor
organizations. The U.S. government team includes:
Boeing Phantom Works, which built the AAR
flight control computer and developed the AAR control
Calspan, which operates the Learjet
Rockwell Collins, which supports KC-135 operations,
builds the Tactical Targeting Network Technologies data link,
and produces the GPS receiver card
L3 Communications, SySense and the Illinois
Institute of Technology, which work with NAVAIR to develop
the precision global positioning system-based relative navigation
Northrop Grumman, which built the INS/GPS,
developed PGPS algorithms, and developed an EO/IR position
General Dynamics Advanced Information Systems,
which provides systems engineering and flight test management
Syngenics, which coordinates the AAR trade
Bihrle Applied Research, which integrates
The Institute for Scientific Research, which
develops image processing algorithms
Coherent Solutions, which develops required