September 1, 1952 — Yaak, MT
8:23 p.m. Air Defense Command radar at Yaak Air Force Station in Montana picks up UFOs exhibiting changes of direction as many as five times a minute. Some course changes are 90° and speeds are measured at 1,400–1,600 mph. Six blips at one time appear on the FPS-3 radar scopes and the strange targets come within 10 miles of the GCI site. So close is the indicated range the radar personnel leave their windowless operations room to check the sky. Six objects can be seen an estimated 10 miles away. When first spotted, the UFOs are in an in-trail formation, and shortly thereafter that changes to an in-line abreast grouping. Finally, the UFOs switch to a vertical stack. S/Sgt. William Kelly remembers tracking the UFOs on the radar executing vertical climbs that exceed the limit of the site’s height-finding equipment.[Eberhart]
Source:
Brad Sparks, Blue Books Unknowns Catalogue, Case 808, p. 170;
Edward Ruppelt, The Report on Unidentified Flying Objects, p. 194;
Richard Hall, The UFO Evidence, p. 85;
Loren E. Gross, UFOs, a History: 1952, September–October, The Author, 1986, pp. 2-3;
Loren E. Gross, UFOs, a History: 1953, August–December, The Author, 1990, p. 5;
NICAP, “Radar/Visual at Air Force Radar Site”;