The X-47B's first takeoff at Edwards AFB, California, in February 2.011
Role :Unmanned combat air vehicle
Manufacturer : Northrop Grumman
First flight : 4 February 2.011
Primary user : United States Navy
Number built : 2
Program cost :US$813 million
Developed from :X-47A Pegasus
Developed into : X-47C UCLASS
The Northrop Grumman X-47B is a demonstration unmanned combat air vehicle (UCAV) designed for carrier-based operations.
Developed by the American defense technology company Northrop Grumman, the X-47 project began as part of DARPA's J-UCAS program, and is now part of the United States Navy's Unmanned Combat Air System Demonstration (UCAS-D) program.
The X-47B first flew in 2.011, and as of 2.013, it is undergoing flight testing, having successfully performed a series of land- and carrier-based demonstrations.
Northrop Grumman intends to develop the prototype X-47B into a battlefield-ready aircraft, the Unmanned Carrier-Launched Surveillance and Strike (UCLASS) system, which will enter service by 2.019.
Design and development
The US Navy did not commit to practical UCAS efforts until 2.000, when the service awarded contracts of US$2 million each to Boeing and Northrop Grumman for a 15-month concept-exploration program.
Design considerations for a naval UCAV included dealing with the corrosive saltwater environment, deck handling for launch and recovery, integration with command and control systems, and operation in an aircraft carrier's high-electromagnetic-interference environment.
The Navy was also interested in procuring UCAVs for reconnaissance missions, penetrating protected airspace to identify targets for following attack waves.
The J-UCAS program was terminated in February 2006 following the US military's Quadrennial Defense Review.
The US Air Force and Navy proceeded with their own UAV programs.
The Navy selected Northrop Grumman's X-47B as its unmanned combat air system demonstrator (UCAS-D) program.
A new weapon system will not be developed for the X-47B, but it will be able to carry existing weapons,and has a full-sized weapons bay.
To provide realistic testing, the demonstration vehicle is the same size and weight as the projected operational craft.
The X-47B prototype rolled out from Air Force Plant 42 in Palmdale, California, on 16 December 2.008.
Its first flight was planned for November 2.009, but the flight was delayed as the project fell behind schedule.
On 29 December 2.009, Northrop Grumman oversaw towed taxi tests of the aircraft at the Palmdale facility,with the aircraft taxiing under its own power for the first time in January 2.010.
The first flight of the X-47B demonstrator, designated Air Vehicle 1 (AV-1), took place at Edwards Air Force Base, California, on 4 February 2.011.
The aircraft first flew in cruise configuration with its landing gear retracted on 30 September 2.011.
A second X-47B demonstrator, designated AV-2, conducted its maiden flight at Edwards Air Force Base on 22 November 2.011.
The two X-47B demonstrators were planned to have a three-year test program with 50 tests at Edwards AFB and NAS Patuxent River, Maryland, culminating in sea trials in 2.013.
However, the aircraft performed so consistently that the preliminary tests stopped after 16 flights.
The aircraft will be used to demonstrate carrier launches and recoveries, as well as autonomous inflight refueling with a probe and drogue.
The X-47B has a maximum unrefueled range of over 2,100 nautical miles (3,900 km), and an endurance of more than six hours.
In November 2.011, the Navy announced that aerial refuelling equipment and software would be added to one of the prototype aircraft in 2.014 for testing.
The demonstrator aircraft will never be armed.
In 2.012, Northrop Grumman tested a wearable remote control system, designed to allow ground crews to steer the X-47B while on the carrier deck.
In May 2.012, AV-1 began high-intensity electromagnetic interference testing at Patuxent River, to test its compatibility with planned electronic warfare systems.
In June 2.012, AV-2 arrived at Patuxent River to begin a series of tests, including arrested landings and catapult launches, to validate the ability of the aircraft to conduct precision approaches to an aircraft carrier.
The drone's first land-based catapult launch was conducted successfully on 29 November 2.012.
On 26 November 2.012, the X-47B began its carrier-based evaluation aboard the USS Harry S. Truman (CVN-75) at Naval Station Norfolk, Virginia.
On 18 December 2.012, the X-47B completed its first at-sea test phase.
The system was remarked to have performed "outstandingly", having proved that it was compatible with the flight deck, hangar bays, and communication systems of an aircraft carrier.
With deck testing completed, the X-47B demonstrator returned to NAS Patuxent River for further tests.
On 4 May 2.013, the demonstrator successfully performed an arrested landing on a simulated carrier deck at Patuxent River.
The Navy launched the X-47B from the USS George H.W. Bush (CVN-77) on the morning of 14 may 2.013 in the Atlantic Ocean, marking the first time that an unmanned drone was catapulted off an aircraft carrier.
On 17 may 2.013, another first was achieved when the X-47B performed touch-and-go landings and take-offs on the flight deck of the USS George H.W. Bush while underway in the Atlantic Ocean.
On 10 july 2.013, the X-47B launched from Patuxent River and landed on the deck of the George H.W. Bush, conducting the first ever arrested landing of a UAV on an aircraft carrier at sea.
The drone subsequently completed a second successful arrested landing on the Bush, but it was diverted to the Wallops Flight Facility in Virginia after an issue was detected, requiring that a planned third landing be aborted.
One of the drone's three navigational sub-systems failed, which was identified by the other two sub-systems.
The anomaly was indicated to the mission operator, who followed test plan procedures to abort the landing.
The Navy stated that the aircraft's detection of a problem demonstrated its reliability and ability to operate autonomously.
In a test attempt on 15 July 2013, a different X-47B demonstrator, designated 501, failed to make a successful flight deck landing on the Bush due to technical issues.
Officials asserted that only one successful at-sea landing was required for the program, though testers were aiming for three, and only two out of four were achieved.
The project was initially funded under a US$635.8-million contract awarded by the Navy in 2.007.
However, by january 2.012, the X-47B's total program cost had grown to an estimated $813 million.
Government funding for the X-47B UCAS-D program will run out at the end of September 2.013, with the close of the fiscal year.
Original proof-of-concept prototype with a 19-foot (5.9 m) wingspan, first flown in 2.003.
Current demonstrator aircraft with a 62-foot (19 m) wingspan, first flown in 2.011.
Proposed larger version with a payload of 10,000 lb (4,500 kg) and a wingspan of 172 ft (52.4 m).
Crew: None aboard (semi-autonomous operation)
Length: 38.2 ft (11.63 m)
Wingspan: 62.1 ft extended/30.9 ft folded (18.92 m/9.41 m)
Height: 10.4 ft (3.10 m)
Empty weight: 14,000 lb (6,350 kg)
Max. takeoff weight: 44,567 lb (20,215 kg)
Powerplant: 1 × Pratt & Whitney F100-220U turbofan
Maximum speed: Subsonic
Cruise speed: Mach 0.9+ (high subsonic)
Range: 2,100+ NM (3,889+ km)
Service ceiling: 40,000 ft (12,190 m)
2 weapon bays, providing for up to 4,500 lb (2,000 kg) of ordnance