Japan Air Lines Flight 1628 generated one of the richest aviation-UFO records ever preserved: live ATC, crew interviews, radar logs, weather-radar claims, military coordination, flight-path changes and two other aircraft asked to look. The evidence is substantial — but the famous “mothership” story is not equally supported by every layer.
Terauchi’s FAA submission includes drawings of the initial luminous objects, the later large “walnut” form and the weather-radar display he said showed a target seven to eight miles away. These are witness documents, not photographs.
The FAA separately interviewed Terauchi, First Officer Tamefuji and Flight Engineer Tsukuba in January 1987. Those interviews are essential because the most dramatic structural claims are not equally shared.
The public package includes selected voice transcripts, flight-path charts and the later radar review. That lets the case be tested minute by minute rather than retold from memory alone.
Reported two luminous objects near the 747, later a much larger dark form, cockpit illumination, possible warmth, and an enormous size comparison. His FAA sketch set depicts the first objects as bright rectangular/jet-exhaust-like forms, a later huge walnut-shaped body, and a weather-radar screen return. These drawings shaped the public story but remain witness reconstructions rather than imaging evidence.
Confirmed seeing anomalous lights but was more cautious about structure and scale. When shown Terauchi’s giant walnut-shaped sketch in later questioning, he did not simply endorse it as the object he had seen. His evidence supports unusual lights more strongly than a resolved mothership.
Reported lights and movement but explicitly remained uncertain about what the object was. His testimony does not independently establish the giant “mothership.”
JAL 1628 asks Anchorage Center about traffic ahead. Terauchi reports unidentified lights near the aircraft.
Elmendorf's Regional Operations Control Center reports an intermittent primary return several miles from the 747.
JAL descends from 35,000 to 31,000 feet; Terauchi reports the object remains in the vicinity.
Anchorage Center approves a full turn to test whether the reported object will remain with the aircraft.
After being briefly lost, Terauchi reports the object again off the left side.
A United Airlines flight is asked to look. It sees the JAL 747 but reports no unusual traffic. The object is then reported gone.
During the encounter, JAL repeatedly asked Anchorage Center whether any traffic was nearby and reported unusual lights at roughly the same altitude. When the crew later said its weather radar showed a target at about seven to eight miles, Anchorage itself did not immediately see a matching target.
At roughly 18:26 local, Elmendorf military controllers briefly reported a primary contact around eight miles from the JAL 747, then lost it. During the later 360-degree turn, ROCC at one point described a “flight of two” and said the extra return appeared to drop back and right of JAL. That contemporaneous call is one of the case’s most interesting sensor details — but it was brief, intermittent and not preserved as a continuous independently tracked craft.
LIVE RECORD · FAA / ANCHORAGE ARTCC / ELMENDORF ROCCThe official record contains intermittent radar discussion. Military controllers reported brief primary returns near JAL 1628, and the crew also reported a target on the aircraft's weather radar. Those are genuine parts of the file.
But the FAA's later technical review did not find a persistent independent target pacing the 747. Some returns were assessed as ordinary uncorrelated primary/beacon phenomena — effectively split or ghost targets produced when a skin return and transponder reply did not associate normally. Other returns were intermittent and not sufficient to establish a continuous unknown aircraft.
The onboard weather-radar indication is also important but limited. Terauchi wrote that, after setting the display to a 20-mile range, a large green round return appeared at roughly seven to eight miles in the same direction as the visual object. Crucially, no recovered weather-radar tape or stored screen image is known: the evidence is the crew’s report plus Terauchi’s later sketch of the display.
Weather radar can display precipitation and other strong reflective targets; it is not a dedicated aircraft-identification sensor. A reported cockpit return therefore supports “the crew said something reflective appeared on the display,” not “a structured craft was independently confirmed.”
The FAA Technical Center later replayed retained ground-radar data and found a high proportion of returns behaved like ordinary correlated beacon/primary traffic, while many remaining beacon-only returns had nearby primaries consistent with known uncorrelated or split-target behavior. The agency reported no radar abnormality requiring a separate pacing craft.
OFFICIAL LAYER · FAA RADAR REVIEW + ROCC RETURNS · CORRELATION DISPUTEDReported by crew / drawn later by Terauchi; no recovered onboard radar recording.
Brief primary contacts, including a momentary “flight of two” call.
Later technical replay favored uncorrelated primary/beacon or split-target artifacts.
Sensor activity overlaps the sighting, but continuous independent tracking was not demonstrated.
The best reading is intermittent sensor support around a real-time pilot report, followed by an FAA review that found no abnormal radar track proving a separate craft remained alongside JAL 1628.
Terauchi requested maneuvering to test whether the object would follow. The 747 performed a full 360-degree turn. According to his account, the large object was lost during part of the maneuver and later reappeared off the left side. During this period, Elmendorf ROCC briefly told Anchorage it was seeing a “flight of two” and that the extra contact appeared to drop back and right of JAL.
The maneuver is useful because it changed the viewing geometry. It is not a controlled intercept experiment: the crew was managing a heavy freighter at night, the object had no measured range, and the radar record did not continuously track an independent target through the turn.
Terauchi's later “two times bigger than an aircraft carrier” estimate therefore rests on assumed range and angular scale rather than direct measurement. It should be preserved as his perception, not converted into a measured dimension.
A United crew was vectored to inspect the area and readily acquired JAL 1628, silhouetted against the remaining sky glow. Shortly before the aircraft crossed, Terauchi indicated the object was essentially ahead of the United jet. The United crew still reported seeing nothing unusual. That geometry makes the negative observation more important than a generic “they saw nothing” summary.
An Air Force C-130 was also asked to look and did not independently confirm the reported large object.
Different positions, timing and visibility conditions limit the negative observation. But it is meaningful evidence against a persistent, enormous, brilliantly obvious craft remaining close to the 747.
Philip J. Klass argued that Jupiter — extremely bright and low in the relevant sky sector — and nearby Mars could account for at least part of the luminous display, especially when viewed through ice crystals or turbulent air from a dark cockpit. More recent technical summaries continue to regard this as a serious candidate for the principal distant lights.
The hypothesis is strongest for persistent bright points, colour changes, scintillation and apparent motion without range cues. It is weakest against the crew’s close-range structure claims, reported cockpit illumination/heat, the weather-radar report and the brief ROCC contacts.
There is also an important witness issue: under FAA questioning, Tamefuji was not able to cleanly distinguish the lights from a star on appearance alone. That does not prove a planetary identification, but it materially strengthens the need to test celestial geometry rather than assuming every light was a nearby craft.
COUNTER-HYPOTHESIS · KLASS / CELESTIAL-OPTICAL RECONSTRUCTION · NOT A COMPLETE ONE-CAUSE SOLUTIONBright celestial objects and atmospheric distortion may explain some distant-light observations, particularly where the other crew members described lights without a resolved body.
The FAA found ordinary radar-processing phenomena capable of explaining some supposed secondary targets.
A mixed explanation — unusual visual lights plus ordinary radar artifacts plus captain-weighted interpretation — fits the evidential structure better than assuming every report was one physical craft.
FAA-era material and later skeptical analyses note that Terauchi had made previous unusual-sighting reports. That fact is often used rhetorically either to dismiss him as a “UFO repeater” or, conversely, to portray him as unusually experienced with anomalous phenomena.
Neither move is evidentially sound. Prior reports may matter when assessing expectation and interpretation, but they do not erase the live ATC record of JAL 1628, and they do not turn his later giant-object description into independent fact. The page treats the prior-report history as witness context only.
JAL 1628 deserves its place among the most important aviation-UFO cases because it happened in controlled airspace, was reported in real time and left behind a substantial FAA record rather than a retrospective anecdote.
The careful reading is more interesting than the legend. Three crew members support an unusual light event. Radar personnel discussed intermittent returns. The aircraft maneuvered. Yet the most dramatic claim — an immense structured “mothership” pacing the 747 — belongs primarily to Captain Terauchi and was not independently confirmed by the United or Air Force crews sent to look.
That leaves a case with genuine documentary depth and unresolved visual testimony, but without the clean multi-sensor confirmation often claimed for it. The record is rich enough that it does not need exaggeration.