I have been flying since 1939 quite a lot of experience RAF +test+airline+triangular aeroplanes. The quick version is that I interpret a photo over albukirque 1 minute before breakup as left main gear down nose door open.Published telemetry data indicates left gear down locked,but uplocks "no change" I therefor believe it possible that gear could have been NOT locked up from some previous time in the flight including lift off , with no unlocked indication at all