On the night of July 31, 1995, Aerolíneas Argentinas Flight 674, a Boeing 727 inbound from Buenos Aires to San Carlos de Bariloche in Argentine Patagonia, was on final approach to Bariloche Airport (ICAO code SAZS) at about 10:15 PM when both the aircraft and the airport's electrical systems lost power simultaneously. The tower blackout occurred at exactly the moment the 727 was on short final; the runway lights, approach lights, and all airport instrumentation failed for approximately 45 seconds. Captain Jorge Polanco executed an immediate go-around and reported observing a bright silver object hovering to the side of the runway at approximately 100 metres altitude. Multiple passengers on the port side of the aircraft observed the object and subsequently provided written statements.
Tower controllers, ground personnel, and passengers reported that the object was elongated, emitted a strong yellow-white light, and moved counter to the aircraft's course during the failed approach. When the 727 climbed to holding altitude the object departed eastward at high speed toward the Cerro Catedral ski-resort massif, after which airport power was restored. Flight 674 landed uneventfully twenty minutes later. The incident was witnessed by more than 100 people at the airport and by residents of adjacent neighbourhoods in San Carlos de Bariloche.
The Argentine Air Force's Commission for the Study of Aerospace Phenomena (CEFAE, now the CEFAe) — a formal governmental UFO-investigation office — opened an investigation the following day. CEFAe's preliminary report, partially declassified in 2011, noted the incident's unusual characteristics and could not identify a conventional cause for the simultaneous airport-wide electrical failure or the hovering object. A subsequent cluster of reports followed across the Bariloche region through the rest of 1995, including additional sightings near Cerro Tronador and along Ruta 40. The Bariloche incident remains Argentina's most important declassified military-UFO case and is widely regarded as the best-documented airliner-UFO encounter in Latin American aviation history.