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JAL Flight 1628

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Case Summary

On 17 November 1986, Japan Air Lines Flight 1628, a Boeing 747 cargo flight over Alaska, reported unusual lights. Captain Kenju Terauchi described two bright structured objects and later a much larger trailing form; the first officer and flight engineer confirmed lights but were more cautious about structure and scale.

Anchorage controllers and military radar personnel discussed intermittent returns. FAA’s later technical analysis found no continuous independent target and considered split images, uncorrelated returns and clutter. A United Airlines flight and a USAF C-130 saw nothing unusual.

The case establishes a documented multi-crew light report with ambiguous radar discussion. The “mothership” interpretation is captain-weighted and not independently verified.

Witnesses

Kenju TerauchiJAL flight crewFAA radar personnel

The 17 November 1986 Record

Visual report

At around 35,000 feet over eastern Alaska, Terauchi saw lights ahead and left, initially thought to be military aircraft. He described pulsing grid-like lights that appeared to illuminate the cockpit and later a large dark outline. Tamefuji and Tsukuba confirmed unusual lights with less definite structure and proximity.

ATC and radar

The crew queried Anchorage Center, which authorised turns and altitude changes. Controllers discussed intermittent returns, but neither civilian nor military radar maintained a stable independent track. Other aircraft were asked to look and reported no visual or radar confirmation.

Aftermath

The flight landed safely. FAA debriefed the crew and reviewed retained radar material. Its analysis did not support a discrete accompanying object; later accounts added more structural and scale detail.

What the record establishes

  • Three crew members reported unusual lights.
  • ATC engaged with the report and intermittent returns.
  • Other aircraft did not corroborate an object.
  • FAA found no continuous independent radar target.

How the JAL 1628 Story Developed

Real-time ATC transcripts are the strongest record for the evolving report. Terauchi’s later interviews carry the most dramatic details. FAA’s technical radar assessment and astronomical reconstructions—placing Jupiter and Mars in the relevant sector—must be considered alongside the crew testimony.

About 17:11 Alaska time

Terauchi notices lights and the crew begins reporting them.

Following minutes

ATC discusses returns and authorises manoeuvres.

Later phase

Terauchi reports a larger object; other aircraft find no confirmation.

1986–87

The FAA investigates the crew reports and available radar information.

Evidence, Documents and Physical Record

Crew

Shared lights, unequal detail

All three saw unusual lights, but the most extraordinary structural and scale claims rest primarily with Terauchi.

ATC record

Real-time reports preserved

Transcripts establish active controller engagement without confirming an object’s identity.

Radar

Ambiguous returns

FAA judged the material compatible with artifacts and did not establish a continuous second target.

Alternatives

Planets and optics matter

Jupiter, Mars, scintillation, ice crystals and cockpit effects form a strong framework for the principal lights.

Evidence Assessment & Hypotheses

The proposed correlation between the crew’s lights and the radar returns carries much of JAL 1628’s physical interpretation. FAA review found the retained returns compatible with known artefacts rather than an independently tracked solid target. Their occurrence during the observation is therefore weaker corroboration than a continuously matched trajectory would have been.

The crew accounts also differ in what they corroborate. Terauchi supplies much of the large-object structure, while the other crew members give more limited support for the luminous observations. Joining every reported feature into one shared sighting would overstate that agreement. Planets, atmospheric effects and cockpit reflections offer relevant optical mechanisms, although a complete reconstruction must address directions and viewing conditions rather than rely on their general availability.

The negative observations from other aircraft further limit the proposed accompanying craft. Residual descriptions of proximity, heat or structure remain questions for optical and perceptual reconstruction, not independent repairs to the sensor chain. The contemporary communications document a legitimate aviation anomaly report whose exceptional scale and formation interpretation lack the confirmation often attributed to them.

Open Questions and Next Steps

Real-time transcript comparison, flight geometry and independent radar reprocessing would best test the residual uncertainty.

Question

How did later accounts change?

Answer

Code ATC transcripts against post-flight interviews, especially the large-object detail.

Question

Where were Jupiter and Mars?

Answer

Time-resolved headings and bank angles can test the optical hypothesis quantitatively.

Question

Can radar be reprocessed?

Answer

Modern review could confirm or refine the FAA artifact conclusion.

1. Publish all crew statements

Clarify shared and captain-specific content.

2. Reconstruct geometry

Integrate flight path, weather and celestial positions.

3. Audit radar

Preserve original recordings and processing assumptions.

Witness Deep Dives

Compare the captain’s interpretation with the more limited supporting observations and technical radar context.

Kenju TerauchiJAL flight crewFAA radar personnel

Source Library

Real-time ATC and FAA technical materials outrank later “mothership” retellings.

Tier 2 Official Investigation

Further references and records

These bibliographic references and record descriptions do not have a direct document link here. Where the discussion relies on a later account of a record, the linked author remains the source for that account.

  • ATC recordings, crew interviews, radar recordings, flight-path and weather data.
  • United Airlines and C-130 statements.
  • Statements of Captain Kenju Terauchi, First Officer Takanori Tamefuji and Flight Engineer Yoshio Tsukuba
  • Astronomical ephemerides and atmospheric-optics literature for the night of 17 November 1986
  • FAA radar-artifact analysis and correspondence.
  • Astronomical, cockpit-optics and radar-artifact analysis.
  • ATC transcripts and FAA technical review of retained radar recordings
  • Giant-craft treatments and planet-only accounts—both should be tested against original records.