Blended Wing Body Demonstrator Aircraft Flying At Higher
Speeds
NASA's Dryden Flight Research Center and Boeing 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, CA. NASA Dryden is
providing critical support to a Boeing-led project team that also
includes the US Air Force Research Laboratory in Dayton, OH 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 20,
2007.
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.
Members of the Boeing Phantom Works research and technology
organization, based in Huntington Beach, CA designed the X-48B
flight test aircraft in cooperation with NASA and the US 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.