The Ota Chipmunk Encounter

When Lieutenant Júlio Miguel Guerra turned to close on the object, it braked hard in front of his aircraft and passed over his head. Then it accelerated away towards the Serra de Sintra and was gone. Guerra was flying a DHC-1 Chipmunk on a training flight over Maxial near Ota Air Base on 2 November 1982. In his account a small metallic disc rose quickly to his altitude and flew tight elliptical orbits around the aircraft at great angular speed. A second Chipmunk was in the air with a crew named Gomes and Garcês, and they confirmed the sighting.

The Portuguese Air Force opened an inquiry with a team of scientists. It found no conventional explanation.

What is on the record

Three claimants are resolved: Júlio Miguel Guerra, Gomes and Garcês. The two crew of the second aircraft are known in the archive by surname only. All three reach the archive through one telling on one channel.

The pilots' account adds three details. No sonic boom was heard, the instruments showed no anomalies, and the object kept one face turned constantly towards the sun.

The case is documented outside the archive. The Air Force inquiry is part of the public record. Guerra later told his own account in Leslie Kean's 2010 book on generals, pilots and government officials who went on the record about UFOs. The case also appears in Portuguese reference lists of sightings. The archive does not yet hold the Air Force's investigation file, and the sighting's date and place on this page follow the public record.

Why it sits where it does

The L3 grade comes from three airmen in two aircraft reporting the same object. A military inquiry could not explain it. If the inquiry's papers enter the archive the case is a candidate for the document-corroborated tier. What circled the Chipmunk over Maxial is not resolved here.