Vicinity North Platte, NebraskaMarch 1960

On the night of March 18, 1960, two Air Force pilots flying a T-33 jet trainer near North Platte, Nebraska spotted three white lights in a line formation at 2055 hours (8:55 p.m.). The lights were about the size of grapefruits and appeared brighter than the surrounding stars and ground lights. Both pilots, Captain William M. MacInnes of the 144th Tactical Fighter Squadron and Captain William W. Diener of the 415th Technical School at Lowry Air Force Base, had good reliability ratings.

The lights first appeared in an 11 o'clock position relative to the aircraft, roughly level with the horizon. They looked similar in size to standard aircraft landing lights. The three objects initially moved from left to right across the sky before disappearing. About five minutes later, they reappeared at a 2 o'clock position, now between 15 and 20 degrees above the horizon. The lights continued moving to the left, disappearing and reappearing at irregular intervals with varying brightness. When they did move, their apparent speed suggested aircraft flying about four miles apart in the opposite direction. The entire sighting lasted five to six minutes.

The Air Force's analysis sheet notes that the pilots mentioned a haze in the area. The official conclusion suggests that an inversion layer or haze may have been present in the atmosphere, causing bright stars or ground lights on or just below the horizon to appear unusually bright and behave in unusual ways. The file states the probable cause was a mirage of bright stars or ground lights created by atmospheric conditions. The full case file, comprising eight pages, is reproduced below as held by the National Archives.