Japan Airlines Flight 1628 and the 1986 Alaska Encounter

On 17 November 1986, Japan Airlines cargo flight 1628, a Boeing 747 freighter, reported being accompanied by unidentified objects over a span of roughly 300 miles across northeastern Alaska, while en route from Paris to Tokyo via a refueling stop. Captain Kenju Terauchi — a veteran with more than 10,000 flight hours — described two walnut-shaped objects flanking the aircraft at close range, and later a much larger object behind them. The crew used onboard weather radar to track the nearest return at an estimated eight miles, and air traffic control at Anchorage reported returns consistent with the crew's descriptions.

The sensor picture

What sets JAL 1628 apart from the great majority of sightings is corroboration. The crew's visual reports occurred over a sustained period with continuous cockpit discussion; the 747's onboard weather radar produced returns at ranges the crew described; and the Elmendorf Air Force Base and regional air traffic control radars logged returns consistent with the reports. Multi-sensor commercial-aviation cases of this kind are rare, and the archive weights them in its highest credibility tier.

The investigation

The Federal Aviation Administration's John Callahan, head of the accidents and investigations branch, led the inquiry. Crew members were interviewed; cockpit voice and radar data were preserved; and the case was discussed at a meeting that included representatives of military intelligence. Callahan later testified publicly that the material was collected and the case closed without a conventional explanation being released. The military's eventual suggestion — that Captain Terauchi had observed the planet Jupiter in his cockpit window — was dismissed by the crew, who noted that the object tracked on their own radar at miles, not astronomical, range.

What the record contains

JAL 1628 sits at the rare intersection of a trained aviation witness, sustained onboard radar, and ground radar confirmation over commercial airspace. As with the 2004 Nimitz encounter, the value of the record is not that the object has been identified — it has not — but that the event was recorded across multiple independent sensors and survived official review without a conventional attribution.