Drone lift-off

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 a potential answer to the threat posed by medium-range anti-ship missiles developed by China and Iran, defence analysts said.

The X-47B has been designed to operate with far greater autonomy than the remotely piloted aircraft currently in use, which has raised concerns among some organisations 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.

With a range of 2,000 nautical miles, 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 defence analyst at the Center for Strategic and International Studies. He described the drone as "essentially a really long-range stealth system."

Test pilots Bruce McFadden (left) and Dave Lorenz stand with their arm-mounted controllers after they successfully launched the X-47B, which is one of only two demonstrator models made by Northrop Grumman Corp and carries the equivalent of two precision-guided bombs.

The stealth drone whizzes through the sky. It roared off the USS George H.W. Bush near the coast of Virginia and flew a series of pre-programmed manoeuvres around the ship before veering away toward a Naval air station in Maryland where it was scheduled to land.

McFadden gives a thumbs-up after successfully launching the drone, which was catapulted from the aircraft carrier using the same sling-shot system that sends manned aircraft aloft.

The launch represented a significant landmark for the U.S. military, but defence analysts are now focused on the next step, when the Navy attempts to use what has been learnt with the X-47B to develop an unmanned aircraft for actual operations.