To me this sounds like a risk for service cart/flight attendant/exiting pilot being overcome and entry gained to the cockpit. Even better a hijacker knows exactly when the opportunity arises as the service cart will be moved into place indicating the dance is about to start.
Furthermore, what's to stop suicide pilot murdering co-pilot behind a locked door?
That might be true, but there is a difference in causing the deaths of passengers somewhere behind the closed doors by crashing the plane — and dealing with flesh and bone co-pilot right here and now.
> Aviation authorities swiftly implemented new regulations that required two authorized personnel in the cockpit at all times, but by 2017, Germanwings and other German airlines had dropped the rule.
But a service cart and flight attendant seems like an entirely ineffective obstacle so what's the point? I think I don't know enough about how this "dance" works to comment, so maybe I'll just shut up :)
Furthermore, what's to stop suicide pilot murdering co-pilot behind a locked door?