* Northrop plane is step forward in autonomous capability
* Strategically important long-range, 'stealthy' drone
WASHINGTON, May 14 The U.S. Navy plans to make aviation history on Tuesday by catapulting an unmanned jet off an aircraft carrier for the first time, testing a long-range, stealthy, bat-winged plane that represents a jump forward in drone technology.
The X-47B, which can carry the equivalent of two precision-guided bombs and fly 2,000 nautical miles in one trip, is due to take off from the USS George H. W. Bush in the Atlantic using the same sling-shot system that sends manned aircraft aloft from the short runways aboard aircraft carriers.
Because of its stealth potential and a range nearly twice that of the F-35 Joint Strike Fighter, the X-47B and its successors are seen as one potential answer to the threat posed by medium-range anti-ship missiles developed by potential rivals like China and Iran, defense analysts say.
The missiles and other so-called anti-access, area denial weapons would force U.S. aircraft carriers to operate far enough from shore that F-35 and F/A-18 aircraft would have to undergo refueling to carry out their missions, leaving them vulnerable to attack.
But an unmanned jet like the X-47B could give the Navy both a long-range strike and reconnaissance capability.
"That makes it strategically very important," said Anthony Cordesman, a senior defense analyst at the Center for Strategic and International Studies. He described the drone as "essentially a really long-range stealth system."
Future variants of the drone could probably be designed for full-spectrum broadband stealth, which means it would be hard for radar to locate it, analysts said. That level of stealth would be one of the drone's major defenses.
U.S. drones currently in use in places like Afghanistan and the tribal areas of Pakistan - like the Predator and Reaper - are not up against any air defenses and are not stealthy aircraft.
Because of its long range and the Navy's need to have it take off and land, day and night, from an aircraft carrier, the X-47B has been designed to operate with far greater autonomy than the remotely piloted aircraft currently in use.
That has raised concerns among some organizations worried about the heavy U.S. reliance on drones in warfare and the rising use of autonomous robots by the American military.
Human Rights Watch, in a report launching its recent campaign against "killer robots," cited the X-47B as one of several weapons that represent a transition toward development of fully autonomous arms that require little human intervention.
The Navy tested the X-47B aboard the carrier USS Harry S. Truman late last year, learning how to move it around the decks and thinking about how to integrate it into flight operations. The plane practiced catapult takeoffs and arrested landings at Patuxent River Naval Air Station in Maryland earlier this month.
Analysts will be to see watching whether the Navy just conducts takeoffs and landings during the testing that begins on Tuesday, or if it attempts to integrate the X-47B's flight into operations with other planes.
"One of the biggest challenges ... of having an unmanned system (aboard a carrier) is just keeping that ... ops tempo going," said Brien Alkire, a senior researcher at RAND's Project Air Force. "I'll be curious to see if do they just do a takeoff and landing or do they really ... integrate it."
The X-47B is a demonstration aircraft built by Northrop Grumman under a Navy contract to test the feasibility of unmanned carrier takeoffs and landings and autonomous aerial refueling. Only two planes were built.
A follow-on program - known as the Unmanned Carrier Launched Airborne Surveillance and Strike System, or UCLASS - is expected to build on what was learned with the X-47B to produce operational aircraft.
An initial request for design proposals is expected to be issued by the Navy sometime this month. Other aircraft makers, from Lockheed Martin and Boeing to General Atomics - are expected to compete to participate.
"The X-47B is a great story," said Mark Gunzinger, a defense analyst at the Center for Strategic and Budgetary Assessments think-tank. "It's a milestone and a step forward for unmanned, carrier based aviation. But I think the real story is what's next. How do we operationalize this capability?"
Gunzinger said with the Navy had a "real opportunity" with the UCLASS to either reproduce the kind of drone already in use by the Air Force, or to develop a new type of aircraft "that can be very stealthy and can accept new missions because it has sufficient payload and a growth potential."