At 5.25am on 6 December 1952, Lieutenant Sid Coleman was watching the main radar scope of his B-29 bomber, which was flying over the Gulf of Mexico. Suddenly, the blip of an unknown object, followed by two other blips, appeared on the screen. Coleman checked their speed: it was an incredible 5,240mph (8,431kmp). The navigator also reported blips on his scope. By the time Coleman had recalibrated his set, Captain John Harter had also registered four unknowns.

As a blip approached on the right, another crew member, Master Sergeant Bailey, peered into the night and saw a blue-lit object streak from the front to the rear of the bomber. A second group of blips appeared on all three scopes, followed by a third group. Bending over his screen, the radar officer saw two UFOs rocketing by on the right. He alerted Staff Sergeant Ferris, who looked out through the waist blister. Instantly, Ferris saw two objects streak by, mere blurs of blue-white light.

Up in the cockpit, Captain Harter saw the UFOs cut across the bomber's course, an estimated 40 miles (64km) away. Suddenly, they turned and headed straight towards the B-29. Then abruptly, they slowed to the bomber's speed, turned in behind it and kept pace with it for ten seconds before pulling off to one side. At the same moment, Captain Harter saw a huge half-inch blip on the scope, moving at 5,000mph (8,054 kmh). The smaller UFOs increased their speed, merged with the larger one, and instantly the huge blip accelerated to 9,000mph (14,481kmh) before disappearing.