Fighter plane-size UAVs mature rapidly

Unmanned aircraft have been used in combat for years, but they have either been large reconnaissance platforms or smaller surveillance/attack types. The next generation of robotic aircraft is taking shape and it consists of fighter-jet sized aircraft designed to operate in heavily contested airspace to attack high-value targets.

An update on the progress of two of the most mature of these programs was provided Aug. 16 by top aerospace industry officials at the Association of Unmanned Vehicle Systems International Conference in Washington D.C.

The two platforms are Boeing’s Phantom Ray and Northrop Grumman’s X-47B unmanned combat aerial system (UCAS). The Phantom Ray is a company-sponsored technology demonstrator, and the X-47B is part of a Navy program. Both aircraft made their initial flights this year.

Developed with company funds, the Phantom Ray is a one-off UCAS platform built to demonstrate the firm’s expertise in the field and to showcase its rapid prototyping and development techniques, said Craig Brown, Boeing’s Phantom Ray program manager. An evolution of the platform originally created for the cancelled Defense Advanced Research Projects Agency’s Joint Unmanned Combat Aerial Systems (J-UCAS) program, the Phantom Ray went from concept to flying prototype in about three years. There are still very few fighter-sized unmanned aerial systems, he said.

The aircraft is designed for a variety of missions such as intelligence gathering, surveillance and reconnaissance, suppression of enemy air defenses, electronic attack, and hunter-killer missions. It is a stealthy flying-wing shaped aircraft that is 36-feet long and has a 50-foot wingspan capable of cruising at 614 miles per hour at an operational altitude of 40,000 feet. Key to its intended role, the Phantom Ray can carry up to 4,500 pounds of ordinance, extra fuel and/or sensors in its payload bays. The bays are large enough to accommodate two 2,000 pound Joint Direct Attack Munition satellite guided bombs.

Besides being a stealthy attack demonstrator, the Phantom Ray is also designed to be autonomous. The aircraft’s pilot station consists of “a keyboard and a mouse,” Brown said. The aircraft is designed to manage most of its flight capabilities, such as takeoff, landing and course alterations while leaving human operators in the loop for important decisions such as deciding to attack a target.

Another offshoot from DARPA’s J-UCAS program, Northrop Grumman’s X-47B is undergoing evaluations as part of a Navy program to develop a carrier-based UCAS system. Like the Phantom Ray, the X-47B is highly autonomous, which is vital for its intended role taking off and landing on aircraft carriers. “An unmanned autonomous carrier capable aircraft is different from a manned [remotely piloted] vehicle,” said Carl Johnson, deputy program manager for Northrop Grumman’s Unmanned Combat Aerial System Demonstration program.

In development since 2000, the X-47B is designed to operate in a harsh naval environment. The aircraft is reinforced to withstand the shock of carrier landings, and its dimensions are suited to transiting cramped carrier hangar spaces and elevators. The aircraft also has a 2,400 mile range and a 4,500 pound payload capacity for strike operations.

Like the Phantom Ray, the X-47B is designed to be highly autonomous. This is important in the crowded, moving environment of an aircraft carrier’s deck, where the aircraft must maneuver around and respond to human personnel—something that cannot be done remotely by a pilot, Johnson said.

Autonomy also extends to operations in defended airspace, where the aircraft must be able to identify and maneuver around threats in real time. Human operators must remain in the loop, but the aircraft’s autonomy can be scaled to the operation. Because of these needs, the X-47B has a robust data processing capability. “You’re not accessing the computer on your desk [to control the aircraft], you’re accessing the server on the airplane,” he said.