 FACT: The flight attendant is shown entering the cockpit through the  use of a keypad on the forward wall next to the cockpit door. There  are no keypads in actual aircraft as that would defeat the purpose  of having a security door, since a hijacker could possibly get the  code by watching the crew enter, or by forcing a cabin crew member  to open it under threat. The cockpit door is controlled electrically  (or mechanically) by the flight deck crew only. This is a  requirement of the hardened cockpit door design.