United Kingdom · over Labrador (Canada).BOAC 'Centaurus' · over Labrador

British Overseas Airways Corporation (BOAC) flight 510-196 had departed New York on the afternoon of June 29, 1954, bound for London with a refueling stop at Goose Bay, Labrador. Aboard the Boeing 377 Stratocruiser named 'Centaurus' were 51 passengers and 11 crew, commanded by Captain James Howard, a vastly experienced pilot: a former squadron leader of the British Royal Air Force, with some 7,500 hours of commercial flying and 256 Atlantic crossings to his name. Toward dusk, flying at about 5,800 meters (19,000 feet) over the Labrador coast, Howard and his first officer Lee Boyd noticed, against the still-bright sky off the aircraft's left side, a strange formation: a large dark mass that seemed to change shape (stretching, shrinking, mutating in silhouette) accompanied by six or seven smaller objects moving around it like a disciplined swarm.

The objects held their relative position to the aircraft for about eighteen minutes, over roughly 130 kilometers of flight, effortlessly matching the Stratocruiser's speed. Howard described the large object as continuously changing shape, with the smaller ones seeming to enter and leave it or rearrange beside it. Most of the flight deck crew and several passengers watched it, and Howard had the presence of mind to sketch by hand what they saw as it happened. The crew reported by radio to Goose Bay; according to period accounts, a fighter (an F-94) was put on alert or scrambled to intercept, and as the aircraft neared its destination the small objects seemed to merge into the large one, which then shrank and vanished.

On the ground, during the Goose Bay stop, U.S. Air Force intelligence officers interviewed Howard and his crew. By the time they reached London the story had already hit the British press, and on arrival Howard gave interviews; the BBC preserves footage in which he reproduces his sketch of the object. There was also a disputed instrumental component: several sources hold that the objects were detected on radar at the USAF air station in Cartwright, Labrador. That point was never documented with an accessible primary radar record, so it is cited with caution. The Project Blue Book file (1954-06-8714325) holds the military telex of the time: the pilot of aircraft G-ALSC saw 'one large object with five or six smaller ones around it' for about 18 minutes, from 0105 to 0123 GMT, at 51°53'N 63°10'W and 19,000 feet, some 10 miles off his port side; 'when we and fighter got contact with the a/c objects faded', and ten other crew members verified it. The same file carries two 1954 evaluations: a first report rated the sighting 'unknown natural phenomena, possibly a mirage', since a temperature inversion in the area made it possible, and the USAF's Air Technical Intelligence Center (ATIC) closed it as 'inversion reflection of the planet Mars'. The latter fits poorly with the telex geometry: by this file's own calculation for the place and time, Mars was very low in the southeast (azimuth ~145°, ~3° altitude), on the starboard side of an aircraft flying northeast, whereas the objects were seen to port, toward the northwest, where the Sun had just set. Another message in the file, describing a yellowish object at a bearing of 144° identified at the time as a planet, adds that 'no mirage effect had been announced during the day'. The prosaic explanations offered over the years (a mirage, a lenticular cloud deforming in the dusk light, an atmospheric optical illusion) account for the large object's shape-shifting but fit less well with the small objects holding formation and with the phenomenon's persistence over 18 minutes. The case was left without an explanation that closed the file to the crew's satisfaction.

James Howard was a former RAF squadron leader commanding an airliner, trained precisely to identify what is in the sky, and he observed together with his entire flight-deck crew and part of the passengers, for eighteen continuous minutes, with time to sketch the phenomenon as it happened.

The case also illustrates the limit of visual evidence even under optimal conditions. Unlike a case with a calibrated sensor, here the record is a hand drawing and the concordant testimony of professionals. The most serious prosaic hypothesis (a lenticular cloud or an atmospheric mirage of the dusk light) elegantly explains the large 'shape-shifting' object, and should not be dismissed; its weak point is the retinue of six or seven small objects holding formation, which a cloud does not produce. The element that would have closed the case one way or the other (the alleged radar contact at Cartwright) is cited in the literature but never surfaced as a verifiable primary record, so the file is left with a multiple visual observation and an unconfirmed instrumental record.