The aircraft was operating a scheduled passenger service between London Heathrow Airport and New York JFK Airport. While cruising at Mach 2.0, FL 547 (54.700 feet), close to 47 N, 50øW, off the coast of Newfoundland, the crew felt ‘vibration plus a thump’. Scrutiny of the instruments and available indications revealed nothing untoward. The commander suspected that a section of flying control might have become detached and went aft to conduct a visual inspection. At that time, the aircraft had about 38 tonnes of fuel on board and was some 1 hour 22 minutes to destination. Only the outer and middle elevons are visible from the cabin and they were seen to be intact and reacting normally. There was a continuous slight vibration felt in the cabin, similar in feel to light turbulence. As the aircraft was otherwise performing normally, the commander elected to continue supersonically to the planned destination. The normal flight profile was followed up to the Deceleration Point. In anticipation of increased vibration during transonic flight, the crew reduced thrust to idle power below Mach 1.8 to expedite passage through that regime. At around Mach 1.0, there was more noticeable vibration felt. This subsequently decreased as the aircraft reduced speed further. The remainder of the flight and the landing were normal, the aircraft landing with about 15 tonnes of fuel remaining. During taxi-in, ATC reported that a piece of the aircraft’s rudder appeared to be missing.