A. The crash in the Alps has launched a search for a solution to the problem of accessing the cockpit from outside if the plane has been commandeered from within.
B. Flight safety has so far focused on threats from the passenger side, and the 9/11 terror episode led to fortification of the cockpit.
C. But if they are in a position to act, pilots can override this mechanism.
D. In exceptional circumstances, such as an emergency affecting the pilot and the cockpit area, the crew can use a code that opens the cockpit door briefly, or it even opens automatically if the pilots are immobilized due to depressurization.