Overview
17 November 1986
Japan Air Lines Flight 1628 was a Boeing 747 cargo flight that reported unusual lights while flying over Alaska.
Captain Kenji Terauchi initially described two bright objects near the aircraft and later reported a much larger dark or luminous object behind or alongside the 747. First Officer Takanori Tamefuji and flight engineer Yoshio Tsukuba also reported lights, although their descriptions were less dramatic than Terauchi's.
Anchorage air-traffic controllers attempted to verify the objects through civilian and military radar. Intermittent returns were discussed, but later FAA analysis attributed them to radar clutter, split images or the JAL aircraft itself. A United Airlines flight and a U.S. Air Force C-130 were asked to look for the object but did not report seeing it.
Skeptical investigators have argued that the principal lights were Jupiter and Mars, distorted by atmospheric conditions and cockpit-window reflections. The case remains controversial because the crew clearly reported something unusual, but the evidence for a giant accompanying craft depends primarily on Terauchi's perception.
Historical Context
In 1986:
- Polar cargo routes routinely crossed remote Alaskan airspace.
- Air-traffic radar coverage was extensive but not uniform.
- Military radar systems monitored parts of Alaska.
- Bright planets viewed through ice-crystal layers could appear distorted.
- Civilian pilots were expected to report unidentified traffic that might present a collision risk.
- FAA officials had no dedicated UFO program but investigated aviation-safety implications.
Terauchi had previously reported unusual aerial objects, a fact later cited by critics as evidence that he was predisposed to interpret ambiguous lights as spacecraft.
Timeline
17 November 1986
Flight 1628 was travelling from Paris toward Tokyo with a planned stop at Anchorage.
The Boeing 747-200F carried three crew members.
Approximately 5:11 p.m. Alaska Time
While flying at approximately 35,000 feet over eastern Alaska, Terauchi noticed lights ahead and to the left.
The crew initially considered whether they were military aircraft.
Two Smaller Objects
Terauchi described two objects flying near the aircraft.
He later stated that they:
- Displayed rectangular or grid-like luminous areas.
- Pulsed yellow, amber or white.
- Moved in formation.
- Appeared close enough to illuminate the cockpit.
- Produced a sensation of heat on his face.
Tamefuji and Tsukuba confirmed bright lights but did not clearly see the detailed structures described by the captain.
Contact with Anchorage Center
The crew asked controllers whether radar showed nearby traffic.
Controllers initially reported no confirmed target.
The aircraft was authorized to turn and change altitude.
Larger Object
Terauchi later reported a much larger object, described as comparable in size to an aircraft carrier, following the 747.
He said that its outline was dark but that lights revealed its presence.
Radar Discussion
Controllers and military personnel discussed intermittent radar returns near the aircraft.
The returns were not stable enough to establish a continuous independent target.
Evasive Manoeuvres
Flight 1628 descended and completed turns.
Terauchi's later statements about whether the object remained visible throughout the manoeuvres differed from portions of the air-traffic transcript.
Other Aircraft
A United Airlines flight and an Air Force C-130 entered the general area.
Their crews did not report seeing an unidentified object.
Landing and Interviews
Flight 1628 landed safely at Anchorage.
FAA investigators interviewed the crew.
Officials described the men as professional and rational but did not identify an external craft.
Principal Witnesses
A. Captain Kenji Terauchi
Senior JAL pilot.
Reported:
- Two luminous objects.
- A much larger trailing object.
- Structured light panels.
- Apparent heat.
- Prolonged formation flight.
- Radar confirmation.
Terauchi's account was the most dramatic.
His later interviews contained details not clearly shared by the other crew members.
B. First Officer Takanori Tamefuji
Reported unusual lights.
His estimate of distance and his description of structure were more cautious than Terauchi's.
He did not clearly confirm an aircraft-carrier-sized object.
C. Flight Engineer Yoshio Tsukuba
Also observed lights.
He provided partial corroboration but did not report all of Terauchi's claimed features.
D. Anchorage Air-Traffic Controllers
Communicated with the flight and attempted radar verification.
They observed or received intermittent returns but did not maintain a stable track of an independent object.
E. United Airlines and Air Force Crews
Asked to look for the reported object.
They did not visually confirm it or detect it independently on radar.
Physical Evidence
Evidence includes:
- Air-traffic-control recordings and transcripts.
- FAA interview reports.
- Crew sketches.
- Civilian and military radar records.
- Flight-path and weather data.
- Statements from other aircraft crews.
- FAA correspondence.
No photograph or video was taken.
No physical trace was produced.
No continuous radar track showed an object accompanying the aircraft.
No damage to the 747 occurred.
The case therefore combines testimony with ambiguous, rather than confirmatory, radar information.
Official Investigation
The FAA assembled a substantial data package.
Investigators examined:
- Crew reports.
- Radar recordings.
- Air-traffic communications.
- Weather.
- Astronomical conditions.
- Reports from other aircraft.
- Terauchi's previous sightings.
FAA officials concluded that the intermittent radar returns did not establish an independent object.
One return was treated as a possible split image or reflection of the JAL aircraft, while military returns were considered clutter.
The FAA did not classify the event as evidence of an unknown physical craft.
Skeptical Explanations
Jupiter and Mars
Strengths:
- Both planets were visible in the direction of the reported lights.
- Jupiter was bright and low above the horizon.
- Atmospheric scintillation can create pulsation, colour changes and apparent movement.
- The two planets could appear to maintain position relative to an aircraft.
- Terauchi did not clearly account for the planets separately in his report.
Weaknesses:
- Terauchi described lights moving relative to the aircraft.
- He reported apparent structure and heat.
- The crew believed the objects were much closer than astronomical bodies.
- Planets do not explain every reported radar return.
Ice Crystals and Atmospheric Distortion
Strengths:
- Ice-crystal clouds are common over Alaska.
- Refraction can enlarge, duplicate and distort bright celestial objects.
- Cockpit windows can produce reflections or ghost images.
- Similar later reports by Terauchi were attributed to ground lights diffused through ice clouds.
Weaknesses:
- The crew reportedly observed the lights through more than one window.
- A large dark "mothership" requires substantial perceptual interpretation.
- No complete optical reconstruction has reproduced every detail.
Military or Civilian Aircraft
Strengths:
- Aircraft lights can appear unusual at night.
- Closing speeds and turns may create apparent manoeuvring.
- Military traffic may not have been immediately visible to controllers.
Weaknesses:
- No aircraft was identified in the claimed position.
- The lights reportedly remained near the 747 for an extended period.
- The alleged giant object was far larger than a conventional aircraft.
Radar Artifacts
Strengths:
- Returns were intermittent.
- Controllers could not maintain a coherent independent track.
- Split images can appear close to a strong aircraft return.
- Military radar commonly displays clutter.
- Other aircraft did not detect the object.
Weaknesses:
- Radar personnel considered some returns unusual enough to discuss.
- The timing overlapped the crew's reports.
- Supporters argue that independent systems briefly detected corresponding targets.
Perceptual and Expectation Effects
Strengths:
- Terauchi had reported UFOs previously.
- The captain may have influenced the interpretations of the other crew members.
- A dramatic initial interpretation can shape later memory.
- Crew accounts differed when compared in detail.
Weaknesses:
- All three crew members saw unusual lights.
- Reporting an unidentified object could create professional risk.
- Predisposition does not prove that the observation was mistaken.
Arguments from UFO Researchers
Supporters emphasize:
- Three aviation witnesses.
- Long duration.
- Air-traffic communications recorded during the event.
- Intermittent radar returns.
- Reported evasive manoeuvres.
- Apparent proximity.
- The crew's professional competence.
They argue that the radar evidence and multiple witnesses rule out simple astronomical misidentification.
Critics respond that the radar was inconclusive and that only Terauchi described the enormous craft and extraordinary structure in detail.
Modern Historical Assessment
JAL 1628 was a genuine aviation report involving unusual lights.
The evidence strongly supports that:
- The crew saw luminous phenomena.
- Controllers attempted to assist.
- Some ambiguous radar returns occurred.
- No other aircraft visually confirmed a large object.
The claim of a giant mothership is much less secure than the report of two unusual lights.
A combination of bright planets, atmospheric distortion and radar artifacts remains a plausible explanation.
Critical Analysis Guide
A. Compare the Three Crew Accounts
Which details were shared?
Did Tamefuji or Tsukuba independently report the enormous object?
B. Synchronize Radar and Visual Data
Were returns located at the reported bearing and range?
How long did each contact persist?
C. Reconstruct the Night Sky
Where were Jupiter, Mars and bright stars relative to the flight path?
How would they appear during turns?
D. Analyze Cockpit Optics
Could double-pane cockpit windows create reflected or duplicated lights?
E. Review Later Retellings
Which dramatic details appear in the real-time transcript?
Which emerged during later press interviews?
Primary and Secondary Sources
Primary
- FAA data package.
- Air-traffic-control recordings and transcripts.
- Crew interviews and sketches.
- Military and civilian radar records.
- Statements from the United Airlines and C-130 crews.
- Flight and weather records.
Secondary
- Philip J. Klass's analysis.
- Bruce Maccabee's analysis.
- Contemporary UPI and aviation reporting.
- Robert Sheaffer's astronomical reconstruction.
- Later UFO encyclopedias and documentaries.
Overall Assessment
JAL Flight 1628 is a significant pilot-report case because it was documented in real time and investigated by the FAA.
Its strongest evidence supports unusual lights rather than a massive physical craft. Radar information was intermittent and ambiguous, while the most extraordinary descriptions came chiefly from Captain Terauchi.
The case remains unresolved in a limited observational sense, but astronomical and optical explanations are substantially stronger than popular summaries often acknowledge.
Research Record
- Timeframe: 1986
- Witness profile: Flight crew and radar personnel
- Evidence profile: Radar-plus-visual aviation case
- Mapped witnesses: 3
- Case groups: all, military-pilot, radar-visual
- Timeline deep dive: Available in the Event Timeline
Evidence Analysis
These review points define the claims, record limits, competing explanations, and evidence questions that should be checked before drawing a conclusion.
- Compare the captain's interpretation with the crew's supporting observations.
- Review which radar claims were confirmed, disputed, or later qualified.
- Assess viewing geometry, celestial background, and range-estimation uncertainty.
Witnesses
Methodology
UAPRAD separates contemporaneous records, attributable witness statements, physical or sensor evidence, later recollection, and interpretive commentary. The page preserves uncertainty where the record is incomplete and treats absence of identification as a research status rather than proof of any single explanation.
Citations and Source Links
Sources are listed so readers can separate primary documents, institutional records, witness statements, journalism, and later commentary.