Bruce Maccabee:
October 12, 1950; Knoxville, Tennessee (BBU)
11:25 PM. A military radar unit at Knoxville Airport suddenly detected 11, “and possibly more,” unidentified targets moving over the restricted flight zone at Oak Ridge.  This time action was taken.   At 11:30, the radar station commander scrambled an F-82 fighter.  It was in the air nine minutes later.  The fighter was vectored toward two targets and, according to the radar, closed with the targets, but  the pilot saw nothing.  Ground observations also failed to detect anything in the sky.  No unusual objects were seen visually or on radar for the next two days.  Then the “dam broke.” On October 15, at 3:25 PM, three Oak Ridge security guards and a caretaker saw an exceedingly strange object. (See Oct 15 below)

Fran Ridge:
See actual FBI document below, cleaned up by Jean Waskiewicz. For a chronological list of events surrounding Oak Ridge in 1950, see Oak Ridge Page below.

Detailed reports and documents
Confidential FBI letter, Oct 18, 1950, "Protection of Vital Installations" - Bruce Maccabee
NARA-PBB90-634 to 641, UFOs Over Oak Ridge; F-82 Scrambled; Oct 12,15,16, 1950 - Fran Ridge (pdf file)
The Oak Ridge Page