MADISON, WISCONSINDecember 1952

On the evening of December 9, 1952, two Air Force pilots flying a T-33 jet trainer south of Madison, Wisconsin spotted four bright lights arranged in a diamond formation. Captain W. D. Bridges and First Lieutenant J. C. Johnson were at an altitude of 8,000 feet when they saw the objects traveling at an estimated 400 miles per hour on a heading of 130 degrees. The pilots immediately gave chase, accelerating to 450 miles per hour to catch up. They followed the objects eastward across Wisconsin, passing near Janesville and eventually breaking off their pursuit near Racine when fuel ran low. The entire sighting lasted approximately 25 minutes from start to finish.

Throughout the chase, the pilots maneuvered around the objects, passing alongside them, flying beneath them, and falling in behind them. At no point, however, could they see a solid shape or silhouette, even when flying against the lights of Milwaukee. The four lights remained bright white and maintained the same distance apart in their diamond formation, flying straight and level except for one turn from a southeast heading to an east heading. The objects' brightness, speed, and the pilots' inability to identify them as any known aircraft sparked an official investigation.

The Air Force immediately contacted the 755th Aircraft Control and Warning Squadron at Soapberry radar station. The radar operators reported they could clearly track the T-33 on their scope but could not pick up any return from the unidentified objects, despite trying to make contact for twenty minutes after the pilots broke visual contact. Local radar also checked for any aircraft in the area and found no record of transient or local jets that matched the sighting. This radar evidence proved significant because it suggested the objects were not conventional aircraft, which would have been visible on radar as easily as the T-33 itself.

The Air Force investigation concluded that the objects could not have been weather balloons, as they were traveling far too fast. The only conventional explanation that might fit the observed speed would be jet aircraft, but there were no jets recorded in the area at the time, and jets would have shown up on radar. The investigation examined weather conditions, which were favorable for observation, with visibility described as practically unlimited and only a broken cloud layer at 25,000 feet, well above the pilots' altitude. The case was officially classified as unidentified. The full case file of 17 pages is reproduced below as held by the National Archives.