The Northrop Grumman X-47B was developed as part of the Unmanned Combat Air System Demonstrator (UCAS-D) program to validate the feasibility of integrating large, autonomous unmanned aircraft into U.S. Navy carrier air wings. The program evolved from the earlier DARPA Joint Unmanned Combat Air Systems (J-UCAS) effort, which had produced the X-47A Pegasus. In August 2007, the U.S. Navy awarded the UCAS-D contract to Northrop Grumman, leading to the construction of two specific demonstrator airframes, designated AV-1 and AV-2.
Designed as a strike-fighter-sized aircraft, the X-47B features a low-observable (stealth) tailless design with a wingspan of approximately 62 feet and a length of about 38 feet. The aircraft was engineered for full autonomy during carrier operations, enabling it to manage catapult launches, arrested recoveries, and flight deck maneuvering via computer control and real-time data exchange. To support these safety-critical avionics, Northrop Grumman utilized the Wind River VxWorks real-time operating system.
The aircraft is powered by a Pratt & Whitney F100-PW-220U, a non-afterburning, carrier-suitable variant of the low-bypass turbofan engine. While the design was intended for a service ceiling of 40,000 feet and high-subsonic speeds exceeding 600 mph, the Navy imposed strict test clearance limits during naval trials, restricting the aircraft to 15,000 feet and 220 knots for safety.
Flight testing began in early February 2011 at Edwards Air Force Base in California. The X-47B achieved several historic milestones: in December 2012, it conducted sea trials aboard the USS Harry S. Truman; in 2013, it performed the first-ever catapult launches and arrested recoveries by a low-observable unmanned aircraft aboard the USS George H.W. Bush. By August 2014, the Navy successfully integrated the X-47B into cyclic carrier operations alongside manned F/A-18s on the USS Theodore Roosevelt. In April 2015, the program reached a final major milestone when the X-47B completed the first autonomous aerial refueling of an unmanned aircraft, utilizing an Omega Air K-707 tanker. The primary test program concluded in May 2015. Although the X-47B never entered operational service or combat, its successes informed the development of the Unmanned Carrier-Launched Airborne Surveillance and Strike (UCLASS) concept and the subsequent MQ-25 Stingray program.