As the US Air Force AC-130J flies over South Korea’s towering apartment blocks, its powerful cameras can almost see inside windows on the highest floors.Aimed farther afield, the weapons officers on the four-engine aircraft, nicknamed Ghostrider, can pick out objects at 50,000 feet, almost 10 miles away – all potential targets for thebiggest gun ever mounted on a fixed-wing plane.CNN got an exclusive look inside the aircraft, assignedto Air Force Special Operations Command, in early Juneafter it flew from its home base in Hurlburt Field,Florida, for joint drills in South Korea.In a live-fire exercise, the 105-millimeter howitzer pumped out43-pound shells, into a firing range east of Seoul, the force ofeach blast so powerful that it pushed the tail of the 80-ton plane six feet to the right.About eight seconds after firing, the shells hit the range 10,000feet below, sending smoke billowing skyward as the controllers of the big gun watched the results of their handiwork on largevideo...