The O'Hare Airport disc

At about 4:15 p.m. on 7 November 2006, United Airlines ground personnel at Chicago O'Hare — beginning with a ramp employee marshaling Flight 446 — observed a dark grey, revolving disc hovering below the 1,900-foot overcast above gate C17. Over several minutes it was seen by mechanics, supervisors and at least one pilot, described consistently as six to twenty-four feet across and unlit. It then accelerated vertically, leaving a sharply cut circular hole in the cloud deck that several witnesses called the most unsettling part of the sighting.

United initially denied any report existed; FAA tapes obtained by the Chicago Tribune under FOIA record a United supervisor calling the tower about it the same afternoon. The FAA's position, issued without field investigation, was that a weather phenomenon — a hole-punch cloud — was the likely culprit; meteorologists noted in response that the temperatures that day were poorly suited to the ice-crystal mechanism that carves such holes. No radar return was found, consistent with either a sub-radar object over the terminal or with nothing physical at all.

Jon Hilkevitch's Tribune account became, for a time, the most-read story in the paper's online history — demonstrating an appetite the reporting institutions were not built to meet. The case enters this archive as the cleanest modern example of the disposition gap: a dozen professional witnesses at close range, zero official investigation, and an explanation issued from a desk.