US$2.3 million DARPA/US Navy feasibility study contracts were awarded to Northrop Grumman and Boeing on 30 June 2000 for a future US Naval Unmanned Combat Air Vehicle (UCAV-N), to be operable from aircraft carriers. Phase 1A of this contract was completed in March 2001, followed by the US$25 million Phase 1B; Phase 2A contracts for further studies were awarded to the two manufacturers in March 2002, initially for US$10 million each but increased to US$13 million four months later. In April 2003, DARPA decided that Phase 2B, to continue the development period ahead to mid-2005, should require both designs to address the UCAV joint requirements of the US Air Force and the US Navy. The joint programme was retitled Joint Unmanned Combat Aircraft System (J-UCAS) in July 2003, by which time Lockheed Martin had joined the Northrop Grumman team. The eventual selected type is planned to enter the EMD phase within the 2008 to 2010 time frame.
A full-size mockup of the Northrop Grumman design, later dubbed X-47A, was rolled out on 26 February 2001; roll-out of the first flying prototype took place on 30 July the same year, although its maiden flight was not accomplished until 23 February 2003. Primary purpose of this aircraft is to establish suitability of the basic design for carrier use, including arrester wire landings on a simulated carrier deck at the US Naval Air Warfare Center, China Lake, California.
Variants
X-47A: Proof of concept prototype; detailed description applies to this version.
X-47B: Larger and modified development of X-47A as J-UCAS demonstrator. Two ordered under a Phase 2B (modified Phase 2A) DARPA contract announced on 1 May 2003; will be used to demonstrate feasibility of meeting US Air Force and US Navy UCAV requirements. Common objectives include a combat radius of 1,300 n miles (2,407 km; 1,496 miles) with a 2,041 kg (4,500 lb) payload, and ability to loiter for 2 hours over a target up to 1,000 n miles (1,852 km; 1,151 miles) away. Configuration combines basic shape of X-47A with foldable wing extensions for improved aerodynamic efficiency, low-speed handling and precision landing. First flight is targeted for FY06.
Airframe
Stealth design, of all-carbon composites; manufactured by Scaled Composites Inc. Diamond-shape planform, with 55º sweepback on leading-edges and 30º of forward sweep on trailing-edges. Large elevon in centre of each trailing-edge; forward of these (one in each wing upper surface and one in each lower surface) are four `inlaid' moving surfaces that provide a control function similar to that of a split rudder. No tail surfaces. Retractable tricycle landing gear, with twin-wheel main units and single nosewheel, plus retractable arrester hook.
Mission payloads
As appropriate in eventual J-UCAS for surveillance, SEAD or strike missions.
Guidance and control
Preprogrammed. BAE Systems avionics and vehicle management system.
Launch
Conventional wheeled take-off.
Recovery
Conventional wheeled landing with arrester hook, using US Navy's Shipboard Relative GPS autoland system.
Operational status
Under development. Initial X-47A engine runs in December 2001, January and March 2002 followed by first autonomous engine start and shutdown on 18 April 2002. First two (low-speed) taxi tests at China Lake made on 19 July and 6 September 2002. First flight achieved on 23 February 2003.
Specifications
Power plant
One 14.19 kN (3,190 lb st) Pratt & Whitney Canada JT15D-5C turbofan. See under Weights for fuel details.
Dimensions
Wing span 8.47 m (27 ft 9.6 in)
Wing area 36.14 m² (389.0 sq ft)
Length overall 8.50 m (27 ft 10.8 in)
Height overall 1.86 m (6 ft 1.2 in)
Wheel track (between outer mainwheels) 3.02 m (9 ft 10.8 in)
Wheelbase 3.08 m (10 ft 1.2 in)
Weights (design)
Weight empty 1,740 kg (3,835 lb)
Fuel weight: mission 472 kg (1,040 lb)
max 717 kg (1,580 lb)
Max T-O weight 2,678 kg (5,905 lb)
Performance
g limit +3
Prime contractor
Northrop Grumman Unmanned Systems
San Diego, California.
Картинки - вверху тот же макет, внизу художество, изображающее Х-47В на полетной палубе АВ.
