Research Aircraft Based On Blended Wing Body Concept
The innovative Boeing Blended Wing Body (BWB) research aircraft
-- designated the X-48B -- flew for the first time last week at the
National Aeronautics and Space Administration's Dryden Flight
Research Center at Edwards Air Force Base in CA.
The 21-foot wingspan, 500-pound unmanned test vehicle took off
for the first time on July 20 and climbed to an altitude of 7,500
feet before landing 31 minutes later, according to Boeing.
"We've successfully passed another milestone in our work to
explore and validate the structural, aerodynamic and operational
efficiencies of the BWB concept," said Bob Liebeck, BWB program
manager for Boeing Phantom Works, the company's advanced R&D
unit. "We already have begun to compare actual flight-test data
with the data generated earlier by our computer models and in the
wind tunnel."
The X-48B flight test vehicle was developed by Boeing Phantom
Works in cooperation with NASA and the U.S. Air Force Research
Laboratory to gather detailed information about the stability and
flight-control characteristics of the BWB design, especially during
takeoffs and landings.
Up to 25 flights are planned to gather data in these low-speed
flight regimes. Following completion of low-speed flight testing,
the X-48B likely will be used to test the BWB's low-noise
characteristics, as well as BWB handling characteristics at
transonic speeds.
Two X-48B research vehicles have been built. The vehicle that
flew on July 20 is Ship 2, which also was used for ground and taxi
testing. Ship 1, a duplicate of Ship 2, completed extensive wind
tunnel testing in 2006 at the Old Dominion University NASA Langley
Full-Scale Tunnel in Virginia. Ship 1 will be available for use as
a backup during the flight test program, said the company.
Three turbojet engines enable the composite-skinned research
vehicle to fly up to 10,000 feet and 120 knots in its low-speed
configuration. Modifications would need to be made to the vehicle
to enable it to fly at higher speeds. The unmanned aircraft is
remotely piloted from a ground control station in which the pilot
uses conventional aircraft controls and instrumentation while
looking at a monitor fed by a forward-looking camera on the
aircraft.
The Boeing BWB design resembles a flying wing, but differs in
that the wing blends smoothly into a wide, flat, tailless fuselage.
This fuselage blending helps to get additional lift with less drag
compared to a circular fuselage. This translates to reduced fuel
use at cruise conditions. And because the engines mount high on the
back of the aircraft, there is less noise inside and on the ground
when it is in flight.
"While Boeing constantly explores and applies innovative
technologies to enhance its current and next-generation products,
the X-48B is a good example of how Boeing also looks much farther
into the future at revolutionary concepts that promise even greater
breakthroughs in flight," said Bob Krieger, Boeing chief technology
officer and president of Phantom Works.
While a commercial passenger application for the BWB concept is
not in Boeing's current 20-year market outlook, the Advanced
Systems organization of Boeing Integrated Defense Systems' (IDS) is
closely monitoring the research based on the BWB's potential as a
flexible, long-range, high-capacity military aircraft.
"The BWB concept holds tremendous promise for the future of
military aviation as a multi-purpose military platform in 15 to 20
years," said Darryl Davis, Boeing IDS Advanced Systems vice
president and general manager of Advanced Precision Engagement and
Mobility Systems. "Its unique design attributes will result in less
fuel burn and a greatly reduced noise footprint, which are
important capabilities to offer our Air Force and mobility
customers."
NASA's participation in the project is focused on fundamental,
edge-of-the-envelope flight dynamics and structural concepts of the
BWB. Along with hosting the X-48B flight test and research
activities, NASA Dryden provided engineering and technical support
-- expertise garnered from years of operating cutting-edge unmanned
air vehicles.
The two X-48B research vehicles were built by Cranfield Aerospace
Ltd., in the United Kingdom, in accordance with Boeing
requirements.