http://articles.sun-sentinel.com/2002-02-04/news/0202030228_1_cockpit-doors-faa-airliners
“The Federal Aviation Administration has mandated that cockpit doors be able to withstand small arms fire or explosive devices, such as grenades. That is in addition to being sturdy enough to prevent a powerful man from kicking the door open.”
I would imagine the European airlines have similar, if not the same, guidelines. A gang of guys was not going to get that door open.
“...sturdy enough to prevent a powerful man from kicking the door open.”
Mentions only one man, not multiple men. I’m sure 50 guys form ing a battering ram running at 10 mph is going to take down the door.
50 x 175 lbs. is 8,750 lbs. Multiply that number by the kinetic force and that door will come down very easily.
They don’t design those doors to be impenetrable.