Millions of Americans have flown in manned planes that Boeing (BA) has built, but the aerospace giant is also maneuvering to become a key player in the unmanned world.

Boeing's Phantom Eye demonstration drone can fly at 65,000 feet for up to four days, providing persistent intelligence and communications to operators on the ground.

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The defense contractor also has a number of other drones in development, including the Unmanned Little Bird helicopter.

Boeing, which declined to break out its annual drone revenue for CNNMoney, generates about 18% of total sales from military aircraft.

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