X-47A/X47B Pegasus UCAV
![](x_planes/X-47.jpg) Specifications Company-
Northrop Grumman Type- Carrier-based unmanned combat air vehicle (UCAV).
Goals- Naval unmanned
combat air vehicle (UCAV-N) Advanced Technology Program (ATP).
Primary Testing Facility
Research- Mojave Spaceport Dimensions-
Span- 27 ft, 10 in; Length- 27 ft, 11 in; Height- 5 ft, 8 in Max Speed- N/A Range-
N/A Service Ceiling- N/A Power Plant-
Pratt & Whitney Canada JT15D-5C Thrust-
3,190 lbf Weights-
Empty: 3,835 lbs; Loaded: 5,500 lbs Payload-
1,000 lbs Flights- N/A Number of Prototypes Built-
2 (2 X-43A) Project Tenure- 2000-2006 Project Status-
Cancelled Information
The Northrop Grumman X-47A Pegasus is a
demonstration Unmanned Combat Aerial Vehicle. The X-47 is part of
DARPA's J-UCAS project.
Unlike the Boeing X-45, Pegasus development was
company-funded. The initial vehicle carries the designation X-47A; a
follow-on Naval version is designated X-47B.
The proof-of-concept X-47A vehicle was built under
contract by Burt Rutan's Scaled Composites at the Mojave Spaceport. The
roll out ceremony at Mojave was in July 2001 and the first flight was
successfully completed in February 2003. The program was terminated on
January 13, 2006 as part of the US Military's Quadrennial Defense
Review.
The US Navy did not commit to practical UCAV
efforts until the summer of 2000, when the service awarded contracts of
$2 million USD each to Boeing and Northrop Grumman for a 15-month
concept-exploration program.
Design considerations for a naval UCAV included
dealing with the corrosive salt-water environment, deck handling for
launch and recovery, integration with command and control systems, and
operation in a carrier's high electromagnetic interference environment.
The Navy was also interested in using their UCAVs for reconnaissance
missions, penetrating protected airspace to identify targets for the
attack waves.
The Navy went on to give Northrop Grumman a
contract for a naval UCAV demonstrator with the designation of "X-47A
Pegasus", in early 2001. The Pegasus demonstrator looks like a simple
black arrowhead with no vertical tailplane. It has a leading edge sweep
of 55 degrees and a trailing edge sweep of 35 degrees. The demonstrator
has retractable tricycle landing gear, with a one-wheel nose gear and
dual-wheel main gear, and has six control surfaces, including two
elevons and four "inlaids". The inlaids are small flap structures
mounted on the top and bottom of the wing forward of the wingtips.
Pegasus is powered by a single Pratt & Whitney
Canada JT15D-5C small high-bypass turbofan engine with 14.2 kN (1,450
kgp / 3,190 lbf) thrust. This engine is currently in use with
operational aircraft such as the Agusta S211A trainer. The engine is
mounted on the demonstrator's back, with the inlet on top behind the
nose. The inlet duct has a serpentine diffuser to prevent radar
reflections off the engine fan. However, to keep costs low, the engine
exhaust is a simple cylindrical tailpipe, with no provisions for
reducing radar or infrared signature.
The UCAV's airframe is built of composite
materials, with construction subcontracted out to Burt Rutan's Scaled
Composites company, which had the expertise and tooling to do the job
cheaply. The airframe basically consists of four main assemblies, split
down the middle with two assemblies on top and two on bottom.
The Pegasus was rolled out on 30 July 2001 and
performed its first flight on 23 February 2003 at the US Naval Air
Warfare Center at China Lake, California. The flight test program did
not involve weapons delivery, but Pegasus does have two weapons bays,
one on each side of the engine, that may be each loaded with a single
225 kilogram (500 pound) dummy bomb to simulate operational flight
loads. The Pegasus was also used to evaluate technologies for carrier
deck landings, though the demonstrator did not have an arresting hook.
Other issues related to carrier operations involve adding deck tie-downs
without compromising stealth characteristics, and designing access
panels so that they wouldn't be blown around or damaged by strong winds
blowing across the carrier deck.
** Information provided by Wikipedia ** |