ADVANCED UAVs

The U.S. Air Force is probing the aerospace industry for its concepts for a new class of armed, long-endurance unmanned aircraft, called Hunter-Killer.

But most of the aerospace industry's responses--from Northrop Grumman, General Atomics Aeronautical Systems, Aurora Flight Sciences and Lockheed Martin--remain shrouded in mystery.

Roughly, it appears five concepts are being offered. Northrop Grumman aggressively spun up two designs, an unmanned version of Scaled Composites' Proteus research aircraft and a smaller, Global Hawk look-alike. General Atomics Aeronautical Systems is suggesting its new turboprop-powered Predator B for the role. The aircraft is already flying, costs well under $10 million per copy with sensors, has at least 24-hr. endurance and can carry six 500-lb. weapons. Moreover, the company is expected to roll out a twin-jet Predator C early next year that also could fit into the category.

Aurora Flight Sciences and Israel Aircraft Industries teamed on an armed version of a turboprop twin-boom, 8,500-lb. Eagle/Heron 2 which is in full-scale development. Boeing planners did not offer an entry, saying they had their hands full with the X-45C and other unmanned projects.

Lockheed Martin's Skunk Works' officials would say publicly only that they made a response to the request for information (RFI). Other industry officials say the company is offering an unmanned system of conventional wing and tail design with two piston engines in a standard arrangement. However, the Skunk Works also is looking at a pusher-puller concept that would make carriage of centerline payloads easier. Drawing on classic low-observable shaping, the non-stealthy aircraft will be very smooth and streamlined with few external appendages. Cost is expected to be around $8 million. That is a particularly critical issue since the Air Force RFI restricted total cost for the aircraft and sensors to $10 million, with another $10 million for a ground station.

Other target requirements call for a bomb load of at least four 500-lb.-class laser- or GPS-guided weapons as part of a total 3,000-lb. payload and a 35,000-50,000-ft. operating altitude. The RFI was silent on speed and sensor performance.

Only Northrop Grumman officials agreed to talk in-depth about their offering. To contain cost, company planners chose scalable airframes, commercial civil aircraft subsystems and specialized flight and mission software run on standard personal computers hardened for the flight environment.

"The Hunter-Killer UAV program falls into a new class of UAV that is less than a Global Hawk and more than a tactical UAV like the Predator A or Heron I," says Douglas Fronius, one of Northrop Grumman's long-time UAV concept developers. "We approached it from two different directions because it was a request for information and not a proposal."

The first concept is the Model 395, an unmanned version of Scaled Composites' Proteus high-altitude, long-endurance research aircraft that has been flying for about five years around the world often carrying UAV-related payloads. The design is powered by two Williams FJ44-3A commercial business jet engines.