Death by pilot

Stuff reports:

A young German co-pilot locked himself alone in the cockpit of a Germanwings airliner and flew it into a mountain with what appears to have been the intent to destroy it, a French prosecutor says.

The 28-year-old German co-pilot of Germanwings Flight 4U 9525 has been identified as Andreas Lubitz.

However, prosecutors are currently not calling the crash a terrorist act, nor a suicide.

The co-pilot repeatedly turned a dial to override the plane’s autopilot, sending it in a steep descent into the Alps, after the plane’s captain had left the cockpit to go to the toilet.

If correct, this is one of the worse acts of mass murder we have seen.

I thought after MH370 the protocol was that another crew member must enter the cockpit if a pilot wishes to leave – so that there is never a sole person in there?