Phantom Works conducted the flight tests with the New York Air
National Guard 107th Air Refueling Wing, which provided a KC-135R
refueling tanker, and Calspan Corp., which provided a Learjet
equipped with a special Boeing flight control system that allowed
it to fly as an unmanned air vehicle. The flight tests integrate
components on both the tanker and receiver aircraft to demonstrate
that the receiver aircraft (the UAV) can autonomously hold position
relative to the tanker while the tanker executes its standard
air refueling maneuvers.
were conducted with the Boeing flight control system engaged,
which enabled the Learjet to autonomously hold various positions
in space - contact, pre-contact or observation - around the
KC-135R. During a flight on Aug. 15, the Learjet was flown manually
to the contact position behind the KC-135R - the point from
which Air Force aircraft receive fuel from a tanker's refueling
boom. The aircraft's flight control system was then engaged,
said Riley, and it autonomously held the contact position for
23 minutes while the tanker flew two full air refueling orbits,
or holding patterns.
flight test efforts were conducted in August 2004 and September
2005 to evaluate the suitability of the Learjet behind a KC-135
and to take GPS measurements to determine positioning for future
flights. As a prelude to the Station-Keeping Flight Test, some
Learjet inner-loop flight control laws were tested.
The AAR flight
test program will continue through 2007 to complete this phase
of the program and ready the technology for transition to Air
Force assets. Over the next year, the AAR team will build on
the success of the station-keeping flight tests that will lead
to new automated refueling capabilities.
2007, the AAR team will demonstrate autonomous maneuvering around
the tanker. The Learjet will engage the AAR system at the observation
position on the tanker wing and will be directed from a control
station to go to the pre-contact and contact positions upon
approval from the tanker crew.
-- which built the AAR flight control computer, developed the
station keeping control laws, and is conducting the flight tests
-- is the advanced R&D unit of Boeing. Its charter is to
provide innovative technology solutions that reduce the cycle
time and cost of aerospace products and services while improving
their quality and performance.