Program Will End With Transition To Forward Flight
Aero-News has learned
the second X-50A Dragonfly -- Boeing's second canard rotor/wing
(CRW) technology demonstrator –- has successfully completed a
four-minute hover flight at the U.S. Army’s Yuma Proving
Ground in southwest Arizona. The aircraft reached an altitude of
about 20 feet above ground.
"Our first flight test objectives were met today," said Clark
Mitchell, Boeing Phantom Works program manager for the CRW
prototype. "This is a significant achievement toward validating the
new stopped-rotor technology."
Under joint development by Boeing Phantom Works and the Defense
Advanced Research Projects Agency (DARPA), the CRW is a
revolutionary aircraft that combines the speed and range of
fixed-wing flight with the flexibility of rotary-wing flight. It
also incorporates tip jet propulsion and stopped rotor
"The most significant objective met was verification that
software compensation effectively reduces the rotor control issue
we were having, or cross coupling," he said. The phenomenon of
cross coupling was a finding in the mishap investigation of Ship 1
in 2004 that led to wind tunnel tests for Ship 2 at the Boeing
helicopter facility in Philadelphia earlier this year.
Ship 2 then completed ground checkout testing at the Boeing
facility in Mesa, AZ, where it was configured for flight. After a
flight readiness review, the vehicle was shipped to Yuma where it
completed a preparatory "pop up" flight Nov. 4. The flight lasted
only about 30 seconds during which the aircraft stabilized briefly
at 16 feet above the ground and then landed. Success with the
initial flight led to the hover flight Dec. 2.
Mitchell said that flight tests are expected to continue into
early next year. The flight-test schedule calls for 11 flights.
Under the remote control of a pilot in a ground station cockpit,
the X-50A Dragonfly will gradually perform more extensive hover
flights, then forward-moving rotary wing flights.
The test program will culminate with the first ever "conversion"
from rotary wing flight to fixed-wing flight and back again to
rotary wing flight for landing. The conversion requires the main
rotor to stop turning in flight, and lock in place to become a
fixed wing for high speed flight.
Ship 1, the first Dragonfly prototype vehicle, was involved in a
flight mishap on March 23, 2004, that led to a joint investigation
by Boeing and DARPA. The findings identified cross coupling of the
rotor controls as the main cause of the mishap. Since then,
improvements have been incorporated into Ship 2 that address design
issues related to findings. These include changes such as new rotor
torsion springs for increased control power, new flight control
software and a flight data recorder.