UNRESOLVED
CF-GEI-19780401879 UNRESOLVED PRIORITY: HIGH
The Évreux Air Base Radar Contact
CASE FILE — CF-GEI-19780401879 — CASEFILES CLASSIFIED ARCHIVE
Date Date when the incident was reported or occurred
1978-04-23
Location Reported location of the sighting or event
Fauville, Eure, Haute-Normandie, France
Duration Estimated duration of the observed phenomenon
16 minutes
Object Type Classification of the observed object based on witness descriptions
light
Source Origin database or archive this case was sourced from
geipan
Witnesses Number of known witnesses who reported the event
2
Country Country where the incident took place
FR
AI Confidence AI-generated credibility score based on source reliability, detail consistency, and corroboration
85%
On the evening of April 23, 1978, between 20:35 and 20:51 UTC, an operational duty officer at Air Base 105 in Évreux, France received a telephone alert and subsequently observed a red luminous point in the sky. The object was positioned at an elevation between 10° and 15° and estimated to be at bearing 300° relative to the Évreux base. Lookout personnel on the base also observed the phenomenon, noting that its luminous intensity decreased over time. At 20:44 UTC, the duty officer requested radar assistance, which detected an echo at bearing 300° from the station at a distance of 18 nautical miles, moving toward bearing 330° at an estimated speed of 30-40 knots. The radar contact, though weak in intensity (rated 1/5), persisted for 7 minutes—an unusually long duration for such a faint return. Visual observations and radar tracking both ceased at 20:51 UTC.
The officer filed his official report the following day, April 24, 1978. Notably, the radar observation report mistakenly listed the 24th as the observation date, but this appears to be a typographical error, allowing investigators to validate the simultaneity of the visual sighting and radar trace. Unfortunately, no recording of the radar data was preserved. The GEPAN investigation (predecessor to GEIPAN) rejected conventional explanations including helicopter and balloon. Investigators noted that Venus was highly visible that evening at a nearby position (azimuth 296°-299°, elevation 4°-1.5°), yet the observed object's position differed significantly (azimuth 300°-330°, elevation 10°-15°), making misidentification with Venus extremely improbable.
The case presents an intriguing correlation between trained military observers and instrumented data. The weak radar return was not confirmed by the secondary radar at Cinq-Mars-La-Pile, raising questions about the signal's authenticity. GEIPAN classified this case as D1: "moderately strange phenomenon, distant, but testimony of good consistency"—indicating an unidentified aerial phenomenon with credible witnesses but insufficient data for definitive conclusions.
02 Timeline of Events
20:35 UTC
Initial Alert and Observation
Following a telephone call, the operational duty officer at Air Base 105 Évreux begins observing a red luminous point in the sky at bearing 300°, elevation 10-15°
20:35-20:44 UTC
Visual Observation by Multiple Personnel
Lookout personnel (vigie) also observe the phenomenon, noting its luminous intensity is decreasing over time
20:44 UTC
Radar Contact Established
Duty officer requests radar assistance. Radar detects echo at bearing 300°, distance 18 nautical miles, moving toward bearing 330° at 30-40 knots. Signal intensity weak (1/5)
20:44-20:51 UTC
Sustained Radar Tracking
Radar maintains contact with weak echo for 7 minutes—unusually long duration for such low-intensity return. No confirmation from Cinq-Mars-La-Pile radar
20:51 UTC
Observations Cease
Both visual observations and radar tracking end simultaneously. Total duration: 16 minutes
April 24, 1978
Official Report Filed
Duty officer submits formal report. Radar observation report contains typographical error listing incident date as the 24th instead of 23rd
Post-Investigation
GEPAN Investigation and D1 Classification
GEPAN investigators reject helicopter and balloon hypotheses, rule out Venus misidentification, note lack of radar confirmation from secondary installation, classify as D1: moderately strange, unidentified
03 Key Witnesses
Anonymous Duty Officer
Operational Duty Officer, Air Base 105 Évreux
high
Military officer on operational duty at French Air Force Base 105, responsible for monitoring airspace and responding to aerial phenomena. Filed official report on April 24, 1978.
"Position estimée dans le 300 de la base d'Evreux à une hauteur comprise entre 10° et 15°"
Lookout Personnel
Military lookout/vigie personnel, Air Base 105 Évreux
high
Trained military lookout personnel stationed at Air Base 105 who corroborated the duty officer's visual observation.
"Le personnel de la vigie observe également le phénomène dont l'intensité lumineuse décroit"
04 Analyst Notes -- AI Processed
This case demonstrates several factors that elevate its credibility: military witnesses trained in aerial observation, institutional documentation through official Air Force channels, and corroborating radar data coinciding with visual observation. The duty officer's professional background and the involvement of multiple lookout personnel reduce the likelihood of misidentification of common aircraft or celestial objects. The movement characteristics—30-40 knots at relatively low altitude—fall within the range of conventional aircraft, yet the GEPAN investigation explicitly ruled out helicopters based on available evidence.
However, significant uncertainties remain. The radar contact's weak intensity (1/5) and lack of confirmation from the Cinq-Mars-La-Pile installation suggest possible anomalous propagation or secondary reflection rather than a solid target. The absence of preserved radar recordings prevents further analysis. The decreasing luminous intensity observed visually could indicate increasing distance, dimming lights, or atmospheric effects. The case's strength lies in the convergence of visual observation and radar detection during the same timeframe, but the weakness of both signals and the lack of additional corroborating data from other sources prevent a conclusive determination. The object's trajectory and speed are consistent with unconventional aerial activity but not definitively anomalous.
05 Theory Comparison
BELIEVER ANALYSIS
Genuine Unidentified Craft with Low Observability
The convergence of trained military observers, institutional documentation, and corroborating radar data during identical timeframe suggests a genuine anomalous aerial craft. The weak radar signature despite visual observation could indicate advanced low-observable technology or non-conventional propulsion. The object's controlled movement from bearing 300° to 330° at constant speed suggests intelligent control rather than natural phenomena.
SKEPTIC ANALYSIS
Radar Artifact with Astronomical Misidentification
The weak radar return (1/5 intensity) unconfirmed by secondary radar at Cinq-Mars-La-Pile suggests possible spurious echo caused by secondary reflection or anomalous propagation. The visual observation, despite angular discrepancy, could represent atmospheric distortion of Venus (visible at azimuth 296-299°, elevation 4-1.5°) or another astronomical object, with the decreasing intensity consistent with atmospheric effects or increasing distance to horizon.
06 Verdict
ANALYST VERDICT
The Évreux Air Base incident remains genuinely unresolved, meriting its D1 classification. While conventional explanations such as aircraft, helicopter, and balloon have been ruled out by official investigators, and Venus misidentification appears highly improbable given the angular discrepancy, the evidence is insufficient for positive identification. The most significant aspect of this case is the rare simultaneous visual-radar detection from a military installation with trained observers, lending substantial credibility to the reported phenomenon. However, the weak and unconfirmed radar signal introduces reasonable doubt about whether a physical object was present or whether atmospheric conditions produced spurious returns. This case represents a well-documented military encounter with an aerial phenomenon that defied immediate identification, but lacks the robust multi-sensor confirmation and physical evidence necessary to exclude all conventional possibilities. Its significance lies primarily in demonstrating that even professionally staffed military facilities occasionally encounter aerial phenomena that resist straightforward explanation, even with instrumental data.
AI CONFIDENCE SCORE:
85%
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