The X-48B Blended Wing Body flight model lands at Edwards
Photo: NASA / Carla Thomas
5/21/2008 - EDWARDS AFB, CA - NASA's Dryden Flight Research
Center and The Boeing Co. are expanding the flight envelope
for the X-48B blended wing body research aircraft.
Flight tests with the 500-pound, remotely piloted test vehicle
are now in a second phase involving higher speed regimes. The
21-foot wing span test aircraft is flying without its slats
deployed. Slats are flight control surfaces on the leading edges
of wings which, when extended, allow an aircraft to take off,
fly and land at slower speeds.
X-48B flight testing is taking place at NASA's Dryden Flight
Research Center on Edwards Air Force Base, Calif. NASA Dryden
is providing critical support to a Boeing-led project team that
also includes the U.S. Air Force Research Laboratory in Dayton,
Ohio, and Cranfield Aerospace Ltd., of Bedford, England.
“The first flight in the slats-retracted configuration
marked another milestone in aviation history and the performance
of the X-48 aircraft continues to exceed our expectations,”
said Tim Risch, NASA X-48B project manager. “This flight
milestone reinforced the productive relationship of the NASA,
Boeing and Air Force team and NASA's continued commitment to
developing the concepts, tools and technologies for the aircraft
of the future.”
“We want to fully understand the aerodynamics of the
blended wing body design all the way up to and beyond stall,
so that we can learn how to fly a blended wing body aircraft
as safely as any other large transport aircraft with a conventional
tail,” said Norm Princen, Boeing's X-48B chief engineer.
“This latest phase of the flight testing is one more step
in the process and we are looking forward to progressing on
to more risky flight maneuvers in the months ahead.”
Initial envelope expansion flights of the aircraft, known as
Block 1, consisted of 11 flights and incorporated slow-speed
testing with bolt-on leading edge slats in the extended position.
Block 2 flights began on April 4. The X-48B first flew on July
Now with a clean leading edge, the subscale aircraft, dubbed
Skyray, takes off and lands at speeds of about 75 knots compared
to 60 knots in Block 1. Data will be taken up to a maximum speed
of 118 knots.
At least eight flights are scheduled for Block 2. A total of
six phases are slated for the project, each progressively increasing
the level of risk. The final phase, Block 6, is designed to
push the aircraft's flight parameters by testing the departure
limiter, a critical part of the flight control software that
is designed as a safety feature to prevent the aircraft from
departing controlled flight.
NASA's participation in the blended wing body research effort
is focused on fundamental, advanced flight dynamics and structural
design concepts within the Subsonic Fixed Wing Project, part
of the Fundamental Aeronautics Program managed by NASA's Aeronautics
Research Mission Directorate, Washington.
Potential benefits of the aircraft under investigation include
increased volume for carrying capacity, efficient aerodynamics
for reduced fuel burn and possibly significant reductions in
noise due to propulsion integration options. In these initial
flights, the principal focus is to validate the research on
the aerodynamics and controllability of the shape, including
comparisons of the flight data with the extensive wind-tunnel
In addition to hosting the X-48B flight test and research activities,
Dryden provides engineering and technical support – expertise
garnered from years of operating cutting-edge air vehicles.
Dryden assists with the hardware and software validation and
verification process, the integration and testing of the aircraft's
systems and the pilot's ground control station. Dryden's range
group provides critical telemetry and command and control communications
during X-48B flights, while Dryden Flight Operations provides
a chase aircraft and flight scheduling. Photo and video support
complement the effort.
Members of the Boeing Phantom Works research and technology
organization, based in Huntington Beach, Calif., designed the
X-48B flight test aircraft 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
blended wing body design, especially during takeoffs and landings.
Three small jet engines enable the composite-skinned, 8.5-percent
scale vehicle to fly up to an altitude of 10,000 feet. The aircraft
is flown remotely from a ground control station with the pilot
using conventional aircraft controls and instrumentation while
viewing a monitor fed by a forward-looking camera on the aircraft.
Two X-48B research vehicles were built by Cranfield Aerospace
Ltd. Ship 1, a duplicate of the Ship 2 flight test aircraft,
completed extensive wind tunnel testing in 2006 in the full-scale
wind tunnel at the NASA Langley Research Center in Hampton,
Va. Ship 1 remains available for use as a backup during the
flight test program.
Source: NASA Dryden Press Release