In August 1989, Chris Gibson, a Scottish oil-exploration engineer and, at the time, a member of the British Royal Observer Corps (ROC), was working on the oil rig Galveston Key in the North Sea when he noticed an aircraft in the shape of a pure isoceles triangle refuelling from a KC-135 Stratotanker alongside two F-111s.
The unknown aircraft, cruising in a formation northward through Air-to-Air Refuelling Area (AARA) 6A, is what people have come to believe, is the mysterious Aurora hypersonic spyplane. Another possible aircraft, it was thought at the time, was Northrop's A-17 stealth attack plane, which is now known not to have been developped.
Chris Gibson's observation of the mysterious flying triangle is often cited by UFO researchers when the subject of Aurora rises.
