Navy aircraft managers refine requirements in post-Iraq era

Sea Power, Jun 2003 by Burgess, Richard R

The modified UCAV design for what is designated the X-45C is a product of spiral development, or the continuous insertion of new technology as each unit is designed and built. The Boeing Phantom Works is currently demonstrating the X-45A, and had been developing the X-45B when emerging requirements led to the need for more capability, hence the X-45C concept.

"Recent conflicts have indicated a need for greater range and persistence over the battlefield than originally planned, and we were able to quickly respond to our customer's needs," said Darryl Davis, UCAV program director for the Boeing Phantom Works. "This will allow us to more quickly and affordably provide both the Air Force and the Navy with more robust, capable, and operationally representative concepts," he said, "than would have been possible under our previously separate development programs."

The X-45C-the design of which is based primarily on the subsystems and center body of the X-45B design-will incorporate a revised planform that will provide better aerodynamic performance and increased fuel volume, giving the "C" version three times the combat radius that the X-45B would have carrying the same payload. Boeing is assessing the practicality of providing a refueling capability for the X-45C, to provide even greater range and a longer loiter time. The X-45C will in any case be designed to carry a larger payload, including two 2,000-pound Joint Direct-Attack Munitions, than the X-45B.

The naval version of the X-45C will include a strengthened structure and landing gear, an arresting hook, and the avionics needed for precision approach to and landing on an aircraft carrier. The first flight of the X-45C is scheduled for early 2006.

DARPA has awarded Northrop Grumman a contract modification-worth up to $160 million-to build and demonstrate two full-scale X-47B UCAVs, further refinements of the X-47A Pegasus that the company demonstrated in a successful test flight in February 2003. The tail-less, kite-shaped X-47A demonstrated its ability to carry out an approach and landing touchdown on a runway in a manner similar to that required for a carrier landing.

Northrop Grumman Integrated Systems is revising the X-47B design to accommodate the common Navy and Air Force objectives-which, according to a Northrop Grumman press release, include "a combat radius of 1,300 nautical miles with a 4,000-pound payload, and the ability to loiter for two hours over a target up to 1,000 nautical miles away." The company also will develop the UCAVs autonomous control system as well as its mission control system.

The X-47B-with winglets added-is described by Northrop Grumman as a cranked-kite design. The UCAV-N is expected to emerge as a 30,000-40,000-pound-class aircraft, compared to the 5,500-pound X-47A.

The X-47A is not currently scheduled for additional test flights but could be used in the future to demonstrate more UCAV capabilities as well as the technology required for Phase IIA of the UCAV program, which is described by Kenny Linn (director of business development for Northrop Grumman's UCAV program) as a "bridge effort for continuous funding."