On the evening of 5 December 1989, the duty team at Spain’s EVA 10 air-surveillance unit recorded unusual radar displays while Santiago airport relayed a visual report and experienced radio alarms. The surviving operational account gives times, display names, an initial bearing and range, and changes to the equipment’s operating settings. It does not identify a cause or demonstrate that all the observations belonged to one object.
The five-page released dossier is important precisely because those distinctions survive. The visual description reached the radar unit through another controller; nearby civil aircraft did not confirm it. Radar and radio-direction-finding reports followed, but their different reference points cannot be merged into a single measured trajectory. The outcome is Insufficient evidence, rather than a demonstrated aircraft, spacecraft or equipment fault.
The initial relay from Santiago
At 18:48Z, an air-surveillance officer reported a possible UFO in the broad area between Santiago de Compostela and A Coruña. Two minutes later, EVA 10 established telephone contact with the duty controller at Santiago tower. The controller said that the Guardia Civil at Castro had reported something between Castro and Sada.
The description was of a lenticular form moving slowly, with conspicuous bright lights whose appearance changed. The original operational page prints Sada; the later summary renders the place as Sade. Neither page provides an exact observing position, angular size or the original Guardia Civil witness’s own statement.
The shape and lights are consequently attributed to that relayed report. They are not a description made by the EVA 10 operator looking directly at a visible object. A chain of named organisations can preserve a report without making every participant an independent eyewitness.
What appeared on the radar displays
At 19:00Z, after examining the area, the operator recorded a return on both RAPPI and UPA-35 displays. The report calls it a blitz and describes indications in primary and secondary. Its initial position was given as 060 degrees at thirty-two nautical miles, with an indicated height of 57,000 feet on the RHI height display.
Repeated measurements reportedly showed heights reaching 75,000 feet, while the return changed little in position relative to its first detection. These are reported display indications. The released copy contains no original screen photographs, recorded plots, calibration record or independent determination that an airborne body occupied those heights.
That distinction does not erase the radar report. An operational document explicitly records the display behaviour, so the case legitimately carries the radar feature tag. What it cannot support is treating every indicated height as a surveyed physical altitude and then deriving extraordinary performance from it.
Santiago tower coordinated requests through NECORA for nearby civil aircraft to look for the reported object. The log says no positive visual confirmation was obtained. It gives no basis for saying that airline crews saw the lenticular form at the radar position.
Radio alarms and another bearing
At approximately 20:00Z, Santiago tower reported alarms on the emergency frequencies 121.5 and 243.0 MHz. The account also describes radio interference and confused communications involving Santiago, Madrid area control and NECORA. It does not identify a transmitter or establish why those alarms occurred.
At 20:40Z, direction-finding reportedly placed the alarm’s azimuth between 160 and 167 degrees from Santiago. At roughly the same stage, the UPA-35 showed several returns, with three measured at flight levels 290, 320 and 420. The later summary retains these three levels.
The direction-finding bearing concerns the radio alarm and uses Santiago as its reference. The earlier radar entry gives 060 degrees and thirty-two nautical miles in the radar unit’s operational sequence. The file does not convert those references into a common plotted fix. They should not be described as two instruments independently locating the same object in one place.
Likewise, three radar returns at that later stage are not three visually resolved craft. The record supplies no identification, transponder codes, individual tracks or correlated observer statements for them. Its numerical detail is useful, but its missing connections remain significant.
An equipment change and the end of the watch
At 20:45Z, the operator changed the pulse-repetition frequency in the service channel and requested a channel change. According to the original log, no variation in the radar presentation was observed. This was a recorded operational response to the unusual display, not a complete technical diagnosis.
The entry therefore cannot be used to claim that every possible source of interference was eliminated. The surviving pages provide no engineering investigation, comparison with maintenance records or reproduced test explaining what the change could establish under those conditions.
At 21:02Z, tracking and the telephone link with Santiago tower ended. The later release summary says a residual return remained on the RHI until 08:30Z on 6 December without further variation. The final time on the faded original operational sheet is difficult to read; the clearly printed summary is the source for 08:30 here. The end of the coordinated watch and persistence on one display are separate entries, rather than evidence of continuous visual observation overnight.
How the paperwork reached the archive
The original operational account is dated at Noya on 6 December 1989. A covering letter dated 23 October 1992 sends a photocopy in response to a request and explicitly identifies the duty period as 5 December 1989. The modern cover and the dossier number 891205 agree with that date.
The later document index nevertheless describes the enclosed report as issued on 6 December 1987. The underlying report and its forwarding letter contradict that isolated index date. This record is therefore assigned to 1989, with the discrepancy retained instead of silently creating a second incident in 1987.
The 1996 review recommends declassification because it sees no reason to retain classified status. It supplies no substantive explanation of the radar, visual relay or alarms. Archive release is an access decision, not a technical finding that settles their identity.
Assessment and the map
The released material supports a documented radar report accompanied by a relayed lenticular, illuminated appearance. The disc and multiple-lights tags describe that reported appearance, with radar retained for the actual operational entries. No water-interaction tag is inferred from the Galician coastal geography, and no occupants or contact claim appears in these pages.
Insufficient evidence reflects the absence of the original visual witness’s statement, raw radar data and a demonstrated correlation between the radar and radio observations. It does not mean that a particular conventional explanation has been established, or that unexplained instrument behaviour proves an unusual vehicle.
Approximate map area: 42.79, −8.89, a rounded Noia town reference from the Xunta de Galicia’s municipal information. Noya is the reporting locality named by the dossier. The point represents that broad administrative reference, not the radar installation, the Castro–Sada visual area or a measured object location. Military premises are not offered as visitor destinations.
Read Biblioteca Virtual de Defensa, dossier 891205 and the complete five-page release. Physical pages 2–3 hold the later review; page 4 is the 1992 forwarding letter; page 5 is the original operational account. The Xunta de Galicia’s Noia record supplies the town reference. Sources, relevant original images and the archive’s explicit CC BY 4.0 rights statement were checked on 13 November 2026.