Via Air Safety Network, here’s the reported vertical speed of the last minute of flight. Hard to tell what caused such an immediate excursion from level flight. Airbuses have suffered from pitot/static probe issues before, but that usually leads to a less instantaneous excursion. We’ll see eventually. Yes, Russia will have a piece of the investigation, but so will Egypt, France, Germany, Ireland (the plane was leased from an Irish company) and probably some of our own folks.