United States.Minot AFB B-52

In the pre-dawn hours of 24 October 1968, around 03:00-04:30 local time, a sequence of events at Minot AFB (North Dakota) simultaneously involved three elements: a B-52H Stratofortress bomber returning to base, several Minuteman ICBM Launch Facilities of the 91st Strategic Missile Wing, and the security and maintenance teams deployed across the silo complex.

The initial phase was on the ground: missile security and maintenance teams, spread across the silo field, reported lights and objects maneuvering near the launch facilities, particularly in the vicinity of the sites identified in the records as O-6 and N-7. Those reports coincided with a period of anomalous activity on radar and aboard the aircraft.

The B-52 (callsign JAG-31), on approach to Minot, was alerted by RAPCON control to a target. The navigator acquired the contact on the onboard radar at several miles and maintained separation during a standard 180-degree turn; as it began its descent, the object appeared to close rapidly to about one nautical mile and to 'pace' the aircraft for a stretch before dropping off the display. The crew recorded a brief sequence of radarscope photographs during that close approach; independent reviewers later identified frames 771 to 784, captured over about 37 seconds. During the encounter, the bomber's two UHF radios momentarily stopped transmitting and regained function a few minutes later —the final Blue Book report timeline records that the B-52 'regained the ability to transmit' between 04:00 and 04:02.

The incident was documented by the USAF as one of the last cases processed by Project Blue Book before its closure. The radarscope reel, communications logs, crew and ground-personnel testimony, and the silo security teams' reports were preserved. Decades later, investigators Tom Tulien and Jim Klotz reconstructed the case over five years, interviewing numerous witnesses and reviewing declassified files.

The skeptical reading must be presented fairly, because part of the case admits a conventional explanation. Project Blue Book attributed at least some of the visual sightings to bright stars and planets misinterpreted by fatigued personnel on night shift, and proposed that certain returns could be due to anomalous propagation. Radar analyst Martin Shough, however, examined the B-52 radarscope frames in detail, tested the internal consistency of the testimony and official records against the physical evidence, evaluated multiple conventional interpretations of the echoes, and concluded that none of the possibilities was convincing for explaining the whole. The tension between the partial explanation (stars, planets, anomalous propagation) and the resistant elements (the radarscope sequence, the UHF loss, the concurrence with silo activity) is what sustains the case's interest.

It joins two critical corpus patterns in a single file: electromagnetic interference on an aircraft (temporary UHF loss, an echo of the same type as Tehran 1976) and the presence of anomalous activity over nuclear weapons facilities (the same pattern as Malmstrom 1967, already in the corpus). The B-52's radarscope reel is one of the few physical records captured automatically in a case of this type, not dependent on witness memory. The temporal correlation between the airborne episode and the ground teams' reports at the Minuteman silos makes it hard to attribute everything to a single isolated human error.

Honest calibration requires separating the robust from the debatable. The purely visual observations by ground personnel are the most vulnerable to a conventional explanation —fatigue, bright stars and planets, autokinesis— and Blue Book used them to minimize the case. What has resisted technical scrutiny, by contrast, is the combination of the radarscope photo sequence, the documented loss of communications and the simultaneity with activity at the nuclear complex, a set that analyst Martin Shough could not reduce to a common mechanism. For that reason the case's weight for the corpus rests on its instrumental evidence and its nuclear pattern, not on the more fragile visual sightings.