The wreckage field for the Metrojet A321 crash in Sinai is wider than originally reported – about 5km across at present, and in time maybe even more wreckage will be found.
If this report is accurate, it indicates an in-flight break-up of the aircraft, but the cause cannot be determined with certainty at this point.
Causes of in-flight break-up could be related to a missile strike or a bomb on board, but there is no proper evidence for those right now. There has been an “Islamic State” claim of responsibility, but it has not been backed up with any evidence either.
Speculation in the media has begun about a possible fuselage failure caused by damage to the fuselage that was – allegedly – not properly repaired by the airline, causing an explosive decompression and in-flight structural failure. The kind of damage suggested in this speculation is a tailstrike on the runway during landing or take-off. But this is guesswork. It is not based on evidence.
Modern engineering makes aircraft extremely strong, so total in-flight break-up without extreme stress being applied to the structure is impossible. Thousands of Airbus aircraft in this series have been flying since 1988 and no such event has occurred.