The Taverny Triangle

Theoretical Alignment

This case draws a conservative alignment for reasons specific to the record. The observation came from a single witness, lasted somewhere between 10 and 45 seconds depending on which of his accounts is used, and consisted of a dark silhouette with three faint lights against a night sky. Psycho-Social and mundane framing draws the largest share because a brief night-time silhouette sighting is a recognized category for misperception of a minimally lit conventional object, and GEIPAN's own analysis found a small, quiet, low-flying model aircraft or drone physically compatible with the account. That share is capped by the witness's aviation familiarity, which GEIPAN treated as a reason to rule out an airliner, and by GEIPAN's judgment that a model or drone flight there was very unlikely. Extraterrestrial framing draws modest support from the reported silence and airliner-scale size estimate, which both rest on the witness's distance judgment; the witness himself, after searching online, compared the object to the rumoured "TR-3B" aircraft. Interdimensional framing has the least support in this file.

Background

Two separate threads of context bear directly on how this sighting should be read: the ordinary, unremarkable commuter town the witness was walking through that evening, and the far less ordinary military history buried beneath it — a history GEIPAN's own investigators invoked directly when they reached for Paris–Charles de Gaulle Airport's radar coverage as the basis for their leading (if ultimately rejected) hypothesis.

Taverny: A Val-d'Oise Commuter Town

Taverny is a commune of roughly 27,600 residents (per Insee's most recent published count) in the Val-d'Oise department of Île-de-France, sitting about 21 kilometers northwest of central Paris on the edge of the Forêt de Montmorency. Its residents are known locally as Tabernaciens. By 2010, Taverny was a fully residential and commercial commuter town served by two stations on the Transilien Paris-Nord suburban rail line, with nothing in its surface-level character to distinguish it from dozens of other towns ringing the French capital. The witness was in a small wood beside the park of the town's médiathèque and the new police station, about 200 meters from his home and about 2.5 km southwest of the air base, according to GEIPAN's investigation report; he walked his dog there once or twice a week. The spot lies under the runway axis of Charles de Gaulle Airport, where airliners on final approach pass at low altitude.

What Sits Underneath: Six Decades as France's National Air-Defense Command Post

Taverny's distinguishing feature is invisible from the street. Beneath the town, in gypsum quarries first worked commercially in 1815 and used by the occupying Germans in 1941–1944 for an SKF ball-bearing factory, sits Base aérienne 921 (BA921), for about half a century the seat of French air-defense command. The Centre d'Opérations de la Défense Aérienne (CODA) was created there in 1957; the air-defense staff and then the Commandement Air des Forces de Défense Aérienne (CAFDA) followed from 1961; the base itself was created in 1963, when the strategic air forces command (CFAS) also set up on the surface; and in 1967 the underground complex received the Centre des Opérations des Forces Aériennes Stratégiques (COFAS), the operations center for France's airborne nuclear deterrent. The underground works lie some 70–80 meters beneath the Montmorency forest and were built to operate autonomously, with their own power, water and supplies (French Wikipédia, "Base aérienne 921 Taverny").

A Base Already Mid-Wind-Down by January 2010

It would be a mistake, however, to read this sighting as having occurred beneath an active national command post at the height of its power, and this site's research is explicit about the timeline to avoid that impression. CODA and CAFDA were dissolved in 1994, replaced by the Commandement de la Défense Aérienne et des Opérations Aériennes (CDAOA) and its own Centre de Conduite des Opérations Aériennes (CCOA), both of which continued operating from Taverny for over a decade more. But on September 1, 2007 — roughly two and a half years before this sighting — the CCOA relocated to BA942 Lyon-Mont Verdun, the CDAOA itself moved to BA117 Paris, and the associated intelligence center transferred to BA128 Metz-Frescaty. A 2008 military modernization plan announced under Prime Minister François Fillon then scheduled BA921's own closure for 2011, and the base was formally dissolved on July 5, 2011 — when it employed a little over 1,000 people and had more than 650 rooms of accommodation — before being reduced to an "élément air rattaché" (EAR) under BA110 Creil. It was reactivated as an air base on September 4, 2024. In other words: by the evening of January 4, 2010, Taverny's single most historically significant institutional role — as the seat of national air-defense command — had already ended, and the base itself was less than eighteen months from a formally announced closure. Whatever residual staff, administrative functions, or subordinate units remained on-site at the time, BA921 was in every practical sense already a base in decline, not the operational nerve center of French air defense it had been for the preceding half-century.

Two Different Radars, Not One: Untangling GEIPAN's Own CDG Reference

This distinction matters directly for understanding GEIPAN's own analysis of this sighting, and it is worth being precise about it rather than letting two separate things blur together. Taverny's own historical radar significance — CODA, CAFDA, and later CDAOA — concerned a military air-defense fusion center: a command post that aggregated data from a national network of regional detection and control centers (CDCs) into a single strategic picture, not a radar installation of its own sited at Taverny. GEIPAN's own investigation into this sighting, by contrast, does not invoke BA921's air-defense network at all. Its actual technical hypothesis — that a small drone or model aircraft flying at roughly 150 meters' altitude might sit beneath detectable coverage — refers explicitly to the "cône radar du contrôle aérien (CDG)," the air-traffic-control radar coverage of Paris–Charles de Gaulle Airport, about 24 kilometers to the east, covering CDG's own approach and departure corridors rather than the wider national air-defense picture BA921 was built to fuse. This site's research found no indication in GEIPAN's published file that the agency ever actually requested or reviewed radar logs from either system for the evening in question; its reasoning about the "radar cone" is a stated theoretical compatibility calculation — an object flying that low, that far from CDG's own approach paths, would plausibly fall beneath what CDG's radar would routinely register — not a confirmed negative result from an actual log pulled and checked, in contrast to this site's Fauville-Évreux Radar Sighting, where the base radar logged a faint echo on the witness's bearing (though a second radar did not confirm it). Both of these facts — that BA921's own historic radar role is a different system entirely from the one GEIPAN's hypothesis actually invokes, and that the CDG reference itself appears to be calculation rather than a confirmed records check — are worth holding in mind before treating this sighting's location as somehow more radar-adjacent than it actually is.

Complete Timeline

Date	Event
1815	Gypsum quarrying begins at the site later occupied by Base aérienne 921, Taverny.
1941–1944	The occupying German military expands the quarry tunnels for industrial/military use during the Second World War.
1957	The Centre d'Opérations de la Défense Aérienne (CODA) is established at Taverny.
1961	The CAFDA (Commandement Air des Forces de Défense Aérienne) general staff relocates to Taverny.
1963	Base aérienne 921 (BA921) is formally established.
1967	The underground complex additionally houses COFAS, the operations center for France's strategic (nuclear) air forces command.
1994	CODA and CAFDA are dissolved and replaced by the CDAOA and its CCOA, both remaining at Taverny.
September 1, 2007	The CCOA relocates to BA942 Lyon-Mont Verdun and the CDAOA to BA117 Paris; Taverny ceases to be the seat of national air-defense command.
2008	A national military modernization plan schedules BA921's closure for 2011.
January 4, 2010, approx. 7:45 PM	Sighting. Walking his dog in a small wood near the médiathèque, the witness watches an airliner pass on final approach to Charles de Gaulle, then sees a dark triangle with three faint yellow-orange lights cross the sky from east to west, in silence, until houses hide it.
Following days	The witness writes his narrative that evening, phones GEIPAN and emails it on January 7, and returns the completed questionnaire on January 11. No other witness or press report is identified.
July 5, 2011	BA921 is formally dissolved, becoming an air element attached to BA110 Creil.
September 4, 2024	BA921 is reactivated, restoring Forces Aériennes Stratégiques command functions to the site.
Case status as maintained	Final classification. GEIPAN records the case as Class D1: a strange phenomenon of medium consistency, unexplained, with its own best-fitting drone/model-aircraft hypothesis explicitly judged implausible.

Detailed Narrative

An Ordinary Winter Walk, Then a Silent Shape Overhead

According to GEIPAN's investigation report (compte rendu d'investigation, 2013), the witness, then 52, had come home from work by RER and taken his dog to a small wood beside the park of the Taverny médiathèque, about 200 meters from his home, as he did once or twice a week. Airliners on final approach to Charles de Gaulle were passing over the area; he watched one go by, fully lit, with its navigation lights and cabin windows visible, at what he estimated as about 1,500 feet (an A330 in his first accounts, an A320 in his 2013 interview). Shortly afterwards, by his account, he noticed something coming the other way, from east to west, slightly offset from the approach corridor: three pale yellow-orange circles of light, which he at first took for gulls lit from below, keeping formation as they came closer. As it passed, he saw that the lights were circles beneath a dark, matte mass, with a leading edge that seemed to reflect the town's light, and realised it was a solid object. He described the lights as like round street lamps just switched on, before they reach full brightness, and said they cast no reflection on the dark body. He ran about twenty meters to the street to keep it in view and watched it recede westward until the house fronts hid it. He heard nothing, though he noted that the airliner's engines were still faintly audible, the A115 motorway was making a background noise, and youths were shouting on a nearby football pitch. In his questionnaire he gave its closest distance as 500 meters, its speed as 400–600 km/h ("about three times" the airliner's), its altitude as 2,000–3,000 feet, its size as "at least equivalent" to an Airbus A320, and the duration as 10 to 15 seconds.

A Witness Investigators Explicitly Treated as Aviation-Literate

GEIPAN's case summary draws attention to one detail about the witness: he was "très habitué" to observing aircraft. His email called him "fana d'aviation," an aviation enthusiast; his questionnaire listed flying lessons among his hobbies, and in 2013 he told the investigator he had signed up for pilot training four or five months after the sighting. He also said he had served seven years as a volunteer firefighter. His first reaction, he wrote, was curiosity; before the sighting he already found the subject "passionnant." GEIPAN tied his aviation familiarity directly to its rejection of an airliner, saying the observation was not compatible with "the passage of an airliner, especially as the witness is very used to observing aircraft."

A Genuine Investigation, Confirmed Testimony, and a Rejected Best-Fit Hypothesis

The investigation was slow. A first GEIPAN file in December 2012 concluded that a field investigation was needed; an investigator began work on February 14, 2013, interviewed the witness at home on February 24, 2013, and walked the site with him, taking bearings (the object was first seen at about azimuth 72°, elevation 31°, and lost behind a house front at about 299–310°). The investigator then modelled two published departure routes from Charles de Gaulle runway 27L and found that neither matched: departing airliners would appear much higher in the sky and leave in a different direction, and an aircraft low and fast enough to cross the view in under 45 seconds, below about 600 meters, would have been loud. The clear sky the witness described would also have made an airliner's underside easy to recognise. A small, electrically powered model aircraft or ultralight-sized craft could fit: an object about 2.5 meters long at 150 meters, accelerating from about 35 to 150 km/h, would look the right angular size and cross the sky in about the right time, beneath CDG's radar coverage; a petrol engine or a real ultralight would have been noisy. GEIPAN's conclusion, published on its site (last updated November 6, 2014, with a strangeness rating of 0.62), states that the enquiry "allowed the confirmation of the witness's account, its refinement, and gave credit to the witness's statement," that the drone or model hypothesis "could be compatible" with the observation, but that it seemed "very unlikely" for such a craft to fly in an urban area at night on a winter evening, and that the hypothesis was "not retained, for lack of other probative elements." The report notes one inconsistency it could not resolve: in 2013 the witness gave the duration as 30 to 45 seconds rather than 10 to 15, and at constant speed and height either figure implies an angular speed much faster than the airliners, which he did not remark on.

What the 2013 Interview and Reconstruction Added

The February 2013 interview, a cognitive interview partly transcribed in GEIPAN's report, filled in the description in ways the brief 2010 questionnaire did not. The witness said the three lights were not flat glows but shallow half-globes, "like the ceiling lights that are fixed and opaque," with soft edges that sharpened as the object came closer, and a slightly shifting tint, "as if something was moving inside." Behind the lights he could make out, rather than clearly see, a dark mass. What surprised him was that the lights threw no reflection onto that mass, "as if the mass absorbed the reflection," whereas the leading edge did seem to catch light, which he compared to seeing the edge of an unlit metal wing against a faint glow behind it. The trailing edge was a sharp, dark, matte line. He saw no fin as it moved away, and no blinking navigation lights or strobes of any kind. In new drawings made during the interview he said his 2010 sketch, drawn with a computer mouse, had made the angle far too open: the object was longer than wide, "not a delta wing," and at first looked "a bit like the belly of a gull." He thought it was following the A115 motorway, which he called a good landmark.

He also gave the investigator the reasoning behind his first conclusion. What struck him most, he said, was not the shape but that the object flew against the direction of the airliners, "which in aeronautics does not exist," in controlled airspace above a protected military base. Several numbers in his accounts moved between 2010 and 2013. The altitude estimate went from 2,000–3,000 feet to 2,500–3,000 feet, the speed from 400–600 km/h (about three times the airliner's) to 150–200 knots, "the same speed as the aircraft coming in to land," and the duration from 10–15 seconds to 30–45 seconds. The airliner itself was an A330 in his first accounts and an A320 in the interview, which he said passed about two minutes before the triangle.

The reconstruction tested those figures against the geometry of the site. Standing at the two points the witness identified, the investigator measured a first sighting at about azimuth 72° and elevation 31°, near the treetops, and a disappearance behind a house front at an azimuth between about 299° and 310°. He then simulated a Boeing 747 on two published westbound departure routes from runway 27L at Charles de Gaulle. Neither matched: aircraft on the first route stayed about 25° up after a minute and left well to the left of where the witness lost the object, and the object's reported path resembled the first route at its start and the second only at its end. Constrained to the witness's two sightlines, a straight, level, constant-speed path could not produce a 45-second crossing at airliner-like angular speeds. The object would have had to be roughly three times faster across the sky than the airliners, or accelerating, or descending. GEIPAN's tables then scored each hypothesis against colour, shape, trajectory, speed, angular speed, weather, date, time, duration, first sighting, disappearance and noise. The airliner failed on shape, colour, noise and timing. A small, electrically powered model fitted the angular size, timing and silence, while a conventional ultralight failed on shape, colour and noise; nothing independent showed that any model was flying. That is why the published conclusion keeps the model hypothesis as "compatible" while declining to adopt it.

Not to Be Confused With: GEIPAN's 1980 Taverny Case

GEIPAN's archive holds a second, much older Taverny case that should not be confused with this one. In case 1980-08-00784, classified C (not identified for lack of data), several witnesses saw a yellow-orange light pass at very high speed, climbing, over a radio-relay station of the strategic forces base at Taverny at 9:40 PM and again at 10:45 PM on August 7, 1980; no sound was noticed and no trace was found on the vegetation. That 1980 file, not the 2010 sighting, is the Taverny case that involved a ground search.

Key Witnesses

The Five Observables Assessment

The Five Observables framework, developed by the Pentagon's Advanced Aerospace Threat Identification Program to describe performance characteristics beyond known conventional technology, is applied here for comparative consistency across the site's case files. This case registers a single genuine "Present" rating, reflecting both the brevity of the sighting and the limited detail a 10–15 second, single-witness silhouette observation can support.

Assessment: This is a thin Five Observables profile. A brief, single-witness silhouette sighting of a constant-speed object does not generate the behavioural detail (sudden acceleration, sustained hover) that a longer or closer observation can. What the file does register is silence, which the witness himself qualified ("peut-être à cause de l'environnement," perhaps because of the surroundings, with motorway noise and a football match nearby). Low Observability is rated on that silence and on the absence of any instrumented detection, but no radar was ever checked, and GEIPAN's own analysis notes that an electrically powered model would also be quiet.

Evidence Assessment

Why "Open"

This case is stamped Open because GEIPAN's investigation reached an unresolved, plainly stated conclusion: it credited the witness, ruled out an airliner, and declined to adopt its own next-best candidate (a small drone or model) without any accepted explanation. The case's strength is an aviation-literate witness who wrote his account the same evening, and an investigation that tested the airliner hypothesis against real departure routes and found it wanting.

Weighing against that are real limitations. It rests on a single, uncorroborated witness, whose duration estimate changed between 2010 and 2013 in a way the investigator could not reconcile with a constant-speed path. No photograph, video, or physical trace exists. The field investigation came three years after the event. And GEIPAN's "beneath the radar cone" reasoning was a calculation, not a check of logged radar data; nor were model-flying or other records checked. GEIPAN's own wording is that the drone hypothesis "could be compatible" with the observation and was set aside for lack of supporting evidence, not ruled out. Taken together, this is an honestly investigated and honestly open sighting whose evidentiary thinness keeps it toward the lower end of this site's GEIPAN files.

Sensor & Instrumentation Detection Profile

No photograph, video, or live sensor recording of any kind captured this phenomenon. The closest thing to an instrumented record in this case's file is analytical rather than observational: GEIPAN's investigator produced a spherical panorama of the site and three reconstruction videos (the object's appearance, compared trajectories, and a low-altitude trajectory) based on the witness's verbal description, distance estimate, and reported heading — a genuine piece of analytical reconstruction work, comparable in spirit to a forensic scene diagram, but built entirely from testimony rather than from any independent recording device. This site's research found no indication that any actual, logged radar data — from Charles de Gaulle Airport's own civilian air-traffic-control system, from the regional military air-defense network historically fused through Taverny's own BA921, or from any other source — was ever pulled and reviewed for the specific evening of January 4, 2010. GEIPAN's own "beneath the radar cone" reasoning is, on the published record, a stated theoretical compatibility calculation about what an object of the hypothesized size and altitude would plausibly register as, not a confirmed result from an actual records check. That is a meaningful gap relative to this site's other, more instrumented GEIPAN files (compare, for instance, the Fauville-Évreux Radar Sighting, where the base radar logged a faint echo on the witness's bearing, though a second radar did not confirm it) — and one this site flags honestly rather than implying a radar check happened when the published file gives no indication that it did.

It is also worth noting what modern GEIPAN instrumentation this case predates, since several of this site's other, more recently filed French cases benefit from tools this 2010 file could not have used even if investigators had wanted to. GEIPAN's own automated meteor and fireball camera network, FRIPON (Fireball Recovery and InterPlanetary Observation Network), only launched officially in May 2016, six years after this sighting, and would in any case have been of limited use here given the object's reported altitude and behavior are inconsistent with a meteor or bolide. IPACO (Ingestion et Post-traitement Automatisé des Clichés Ovnis), GEIPAN's own dedicated image and video analysis toolkit for photographic UAP evidence, has nothing to process in a case with no photograph or video in the first place. Both absences are structural rather than investigative failures — the case simply has no imagery or fireball-relevant profile for either tool to apply to — but they underline how much of this file's evidentiary weight rests specifically on the credibility of a single testimony, worked through by traditional witness-interview methodology, rather than on any of the instrumented cross-checks this site's more recent GEIPAN files are increasingly able to draw on.

Environmental & Geospatial Context

The witness described the evening as clear and starry, near 0°C and almost windless: "ciel bleu nuit, on voyait toutes les étoiles." GEIPAN's investigator checked the nearest weather records and found the Le Bourget observations ambiguous: about −3°C with a light north-northeasterly wind and good visibility, cloud cover 8/8 at 7 PM and 9 PM but 1/8 at 8 PM, so the sighting may have come during a clear spell. The Moon was about 23° below the horizon and astronomical twilight had ended 43 minutes earlier (GEIPAN; JPL Horizons gives the Moon as about 78% illuminated and 23° below the horizon).

Geographically, the sighting occurred within the built-up residential area of Taverny itself, a dense commuter town on the edge of the Forêt de Montmorency, roughly 21 kilometers northwest of central Paris. The town sits within the wider ring of airspace around two major aviation facilities: Charles de Gaulle Airport, roughly 24 kilometers to the east by straight-line distance, whose runway axis passes over the observation area, and, historically, the underground air-defense command complex of BA921 directly beneath the town itself, though as discussed above that facility had already ceased its national command role some two and a half years before this sighting and had no active radar installation of its own at the surface. The witness stood in a small wood; to the south was a lit football pitch where young people were playing a match, and the A115 motorway, which he thought the object followed, was nearby. He listed no technical installations nearby on his questionnaire.

The broader Val-d'Oise department, of which Taverny forms a part, is a mixed commuter-suburban and rural department on the northwestern edge of the Paris metropolitan area, its skies subject to the ordinary civil and general aviation traffic typical of the outer Paris basin, including regular traffic patterns associated with CDG, Paris–Le Bourget, and several smaller regional aerodromes. None of that ordinary traffic pattern, per GEIPAN's own investigation, offers a ready explanation for a silent, dark, triangular object judged incompatible with a conventional airliner by a witness the agency itself credits as aviation-literate.

Observer Credibility & Occupational Profile

The witness's occupation is not given in the published file. What is recorded is his age (52), his description of himself as an aviation enthusiast, his corrected 10/10 eyesight with non-tinted anti-reflective glasses, and a stated prior interest in the subject: he wrote that he found it "passionnant" and that it would be a blow for the universe if we were alone. GEIPAN's investigator noted his surprise that such a thorough enquiry was being made. GEIPAN's conclusion that its investigation "confirmed," "refined," and "gave credit to" his account is a positive credibility judgment by the agency.

At the same time, the single-witness structure is a real limitation, separate from any question about this witness's honesty or competence. A single account cannot rule out an idiosyncratic misperception: an unusual viewing angle on a conventional object, a mistaken distance estimate that turns a small, near object into a large, distant one, or a perceptual effect in a brief night-time view. The case summary notes that "no other testimony of observation will be collected." The witness himself looked around for anyone else watching and saw only footballers under floodlights. Both a genuinely localized, easily missed phenomenon and a one-observer misperception remain live possibilities.

Physical & Material Assays

No physical trace evidence exists in this case, and none was ever sought: the object was airborne throughout the entire reported observation, at an altitude high enough (whatever its exact value) that no landing, low hover, or ground-level approach of any kind was ever described. Accordingly, this case has no soil, vegetation, or material sample of any kind associated with it, and no metallurgical, isotopic, or trace-chemical assay was performed or would have been applicable given the nature of the sighting as reported.

Historical Precedents & Archive Matches

This case's most useful points of comparison on this site are the other published GEIPAN files describing large, dark, triangular craft — a genuinely recurring morphology in French UAP reporting that this sighting both resembles closely in one respect and diverges from in another.

Villers-lès-Luxeuil: The Closest Structural Match on This Site

The Villers-lès-Luxeuil Triangle (Open, case #252) describes a "large, dark, silent triangular structure" observed at low altitude near a French Air Force base in Haute-Saône — language that, read side by side with this case's own "large dark triangular form," is the single closest morphological match anywhere in this site's published archive. The two cases diverge meaningfully in behavior, however: Villers-lès-Luxeuil's object was reported quasi-stationary at low altitude, carrying one strong forward white light and one fixed red light, while this Taverny sighting describes a constant-speed, level, cross-sky passage with three faint yellow-orange lights, one at the front and two at the rear, and no hover phase. In the Villers-lès-Luxeuil case GEIPAN obtained military radar data and found a Robin DR400 light aircraft and a Mirage 2000-5F exercise from nearby BA116 in the air; it rated the DR400 the better fit but could not reconcile the dark triangular shape and size with either aircraft. No equivalent check of radar, air-traffic or hobbyist-flight records for Taverny on the evening in question appears in the published file; the investigator's analysis of airliners rests on published CDG departure routes.

Douai: The Same Broad Shape Family, a Genuinely Different Sub-Type

The Douai Prison-Adjacent Sighting (Open, case #253) is this site's other published French triangular-craft case, but it belongs to a visually distinct sub-family within the broader "triangle" morphology: a sharp-edged, actively luminous coral/pink-orange equilateral triangle with small lights along its own leading edges, rather than a dark silhouette with lights only at its extremities. Read together, Taverny, Villers-lès-Luxeuil, and Douai sketch out what looks like at least two genuinely separate recurring triangular morphologies in this site's own French GEIPAN archive: a dark, largely unlit body with lights only at discrete points (Taverny, and to a lesser extent Villers-lès-Luxeuil's fixed red/white lights), and a fully luminous, edge-lit structured triangle (Douai). Whether that distinction reflects two genuinely different phenomena, two different lighting configurations on similar underlying technology (conventional or otherwise), or simply the limits of what a single brief nighttime sighting can reliably convey about an object's true lighting scheme, is a question this site's current archive cannot resolve — but the pattern itself, drawn directly from three independently-investigated GEIPAN files, is a genuine and worth-noting structural observation.

A Recurring Investigative Pattern: The Aviation-Literate Witness

This case also joins a small but genuine pattern within this site's GEIPAN archive of investigations that lean specifically on a witness's own aviation background to rule out conventional aircraft. The Fauville-Évreux Radar Sighting's primary witness was an on-duty French Air Force duty officer who asked for radar help during the sighting. This Taverny file's civilian witness plays a structurally similar role on a smaller scale: not a professional credential, but a self-described aviation enthusiasm (he began pilot training a few months later), credited by the investigator, that GEIPAN explicitly used to rule out the single most common conventional explanation before turning to its own drone hypothesis.

Material Analysis

As with the Physical & Material Assays section above, this case involves no physical or trace evidence of any kind. The object remained airborne throughout the entire observation, and no landing, hover, or ground-level approach was ever reported that could have produced a testable trace.

The Conventional Explanation Candidate: Airliner, Drone/Model Aircraft, and Misperception of a Distant Light Source

GEIPAN's own published synthesis for this case is unusually explicit about walking through, and then explicitly rejecting, its own leading conventional candidates in sequence — a genuinely useful structure to follow directly, since the agency's own stated reasoning does most of the analytical work here better than a reconstruction after the fact could.

Conventional Airliner or Commercial Aircraft

GEIPAN's file states that the sighting is "not compatible with the observation of the passage of an airliner," and connects this to the witness's familiarity with aircraft. The investigation report gives the reasons: the modelled CDG departures from runway 27L would appear much higher and leave in a different direction; an airliner low and fast enough to match the timing would have been loud; and in a clear sky an airliner's lit underside would have been recognisable, as the one he had just watched was. This site finds no basis to second-guess that judgment on the record.

Small Drone or Scale-Model Aircraft

This is the candidate this site treats as the most live, even though GEIPAN declined to adopt it. The investigator's calculation — an object about 2.5 meters long at about 150 meters, accelerating from about 35 to 150 km/h — matches the witness's angular size and timing, would be silent if electrically powered, and would sit beneath Charles de Gaulle's radar coverage. What keeps it from being adopted is not a fact that rules it out, but GEIPAN's contextual judgment that such a flight over a town at night in winter is "very unlikely," together with the absence of "other probative elements." The published file does not record any check of model-flying clubs or radar data. If the object was small and close, the witness's estimates of distance (500 meters), size (an A320) and speed would all be scaled up by the same factor, which is the usual way a nearby small object is mistaken for a distant large one.

One piece of period context, not discussed in GEIPAN's file, bears on how common such a flight would have been. France's first dedicated civil drone regulations, the arrêtés of 11 April 2012, came more than two years later, and the first mass-market smartphone-controlled quadcopter, the Parrot AR.Drone from the Paris company Parrot, was unveiled at the Consumer Electronics Show in Las Vegas in January 2010, days after this sighting, and went on sale later that year. Radio-controlled model aircraft, including electrically powered fixed-wing and multi-rotor models, did exist in 2010 in a smaller hobbyist community, so the context makes the hypothesis less routine than it would be today without ruling it out.

Misperception of a Distant Conventional Light Source

A residual possibility, not set out as its own hypothesis in GEIPAN's summary, is that the witness saw some other conventional object under conditions (darkness, a brief window, an unfamiliar angle) that produced an inaccurate impression of shape, size or silence. He first took the lights for gulls lit from below, and birds lit by urban light are a known source of night-time "formations"; but he described a solid dark body and a lit leading edge as it passed, and GEIPAN did not adopt a misperception explanation either.

Related Cases

Further Reading — Recommended Literature

DISCLOSURE: Some links above are affiliate links. If you purchase through them, OverClassified receives a small commission at no additional cost to you. This helps support independent research.

Essential Viewing

No Videos Available

Sources

• GEIPAN (CNES), "TAVERNY (95) 04.01.2010", Case 2010-01-02498 — official case summary
• GEIPAN (CNES), "Compte rendu d'investigation, Taverny (95150) 04 janvier 2010" (25 pp., field investigation of February 2013, with partial interview transcript) and the witness's questionnaire (28 pp.), both listed on the case page; read via the Internet Archive copy of the case page (web.archive.org)
• NASA JPL Horizons, observer ephemeris for the Moon, Taverny, 4 January 2010, 18:45 UT (illumination about 78%, altitude about −23°)
• GEIPAN (CNES), Témoignage, TAVERNY (95) 04.01.2010 — witness testimony summary
• GEIPAN (CNES), official case archive & public portal — geipan.fr
• GEIPAN (CNES), Glossaire du GEIPAN — official classification definitions, A/B/C/D/D1/D2
• GEIPAN (CNES), Son histoire — institutional history: GEPAN (1977), SEPRA (1988), GEIPAN (2005)
• Wikipédia (français), "Base aérienne 921 Taverny" — history of CODA, CAFDA, CDAOA, COFAS at Taverny, 1957–2024
• Wikipedia (English), "Taverny" — commune geography, population, and Base aérienne 921 summary
• Wikipedia (English), "Commandement de la Défense Aérienne et des Opérations Aériennes" — CDAOA institutional background and 2007 relocation from Taverny
• Insee, Dossier complet — Commune de Taverny (95607) — official French national statistics for the commune
• Légifrance, Arrêté du 11 avril 2012 (drone design/use/operator regulation) — official text establishing France's first civil drone regulatory framework, over two years after this sighting
• Wikipedia (English), "Parrot AR.Drone" — unveiled at CES, Las Vegas, January 2010; on sale later in 2010
• GEIPAN (CNES), case 1980-08-00784, "TAVERNY (95) 1980" (classification C), case summary in this site's GEIPAN dataset — the separate 1980 Taverny case discussed in the narrative
• Wikimedia Commons, File: Taverny - vue aérienne 20190824.jpg, photo by Pymouss (2019), CC BY-SA 4.0 — licensing and attribution
• Wikimedia Commons, Category: Taverny — image archive for the commune
• This site, case-files/villers-les-luxeuil-triangle.html — comparative GEIPAN case, closest morphological match (large, dark, silent triangle)
• This site, case-files/douai-prison-adjacent-sighting.html — comparative GEIPAN case, a distinct fully-luminous triangular sub-type
• This site, case-files/fauville-evreux-radar-sighting.html — comparative GEIPAN case with an aviation-literate witness and an actually-checked radar cross-reference
• This site, key-figures.html, entry on Claude Poher — GEPAN founding and early institutional history
• This site, locations/index.html, entry on Toulouse — CNES/GEPAN/SEPRA/GEIPAN institutional headquarters

Corrections (October 2026)

A fact-check against GEIPAN's own case documents (the 2013 investigation report and the witness's questionnaire, read via the Internet Archive while geipan.fr is offline), the case summary, French Wikipédia on BA921 and JPL Horizons found that the earlier version of this page described the object as having two lights at its extremities; the witness described three, one at the front and two at the rear. It also omitted that an airliner on final approach to Charles de Gaulle had passed in the opposite direction minutes before, that the witness gave a duration of 30–45 seconds in his 2013 interview, and that the field investigation took place three years after the sighting. It said weather was not recorded; the witness and GEIPAN's report both describe it. And it attributed to GEIPAN reasons for doubting the drone hypothesis (no operator, no permit, no local drone activity) that GEIPAN did not give; GEIPAN said only that the hypothesis was not retained "for lack of other probative elements."

Following this review, the rating was changed from Open 36 to Open 33 (October 28, 2026), because the higher rating had rested partly on claims corrected or removed above.

Other corrections: the "conical" shape attributed to a GEIPAN technical field could not be found; the witness called it a delta wing. The witness's location, age, interests and later pilot training are now given from the report. Charles de Gaulle is east of Taverny, not east-northeast. The Moon was about 78% lit and 23° below the horizon, not 85% (JPL Horizons; GEIPAN). The computed weather was replaced by the recorded observations. Unsupported BA921 details ("ten regional stations," "nine times the size of metropolitan France," "ten days of autonomy") were removed. The Villers-lès-Luxeuil and Fauville-Évreux comparisons now match those pages. The Top Secret magazine feature, a France 3 article and a CarteOvni page could not be found and were removed; GEIPAN's separate 1980 Taverny case is now described instead. The book credits for Marler (2013, sole author) and Dolan (foreword by Vallée) were corrected. A link that pointed "Charles de Gaulle Airport" to the Taverny location card was removed.