dryriver writes: Boeing has revealed that it has retrofitted retired fighter jets to turn them into drones. It said that one of the Lockheed Martin F-16 made a first flight with an empty cockpit last week. Two US Air Force pilots controlled the plane from the ground as it flew from a Florida base to the Gulf of Mexico. Boeing suggested that the innovation could ultimately be used to help train pilots, providing an adversary they could practise firing on. The jet — which had previously sat mothballed at an Arizona site for 15 years — flew at an altitude of 40,000ft (12.2km) and a speed of Mach 1.47 (1,119mph/1,800km/h). It carried out a series of manoeuvres including a barrel roll and a "split S" — a move in which the aircraft turns upside down before making a half loop so that it flies the right-way-up in the opposite direction. This can be used in combat to evade missile lock-ons. Boeing said the unmanned F16 was followed by two chase planes to ensure it stayed in sight, and also contained equipment that would have allowed it to self-destruct if necessary. The firm added that the flight attained 7Gs of acceleration but was capable of carrying out manoeuvres at 9Gs — something that might cause physical problems for a pilot. "It flew great, everything worked great, [it] made a beautiful landing — probably one of the best landings I've ever seen," said Paul Cejas, the project's chief engineer.