Should aircraft flight deck doors be kept locked during flight? Should they be made bullet proof? Should every flight carry an armed sky marshal? Could any or all of the forgoing have prevented the tragedies of September 11th? The questions were asked around the world as civil aviation authorities debated what had to be done to prevent a repetition of the World Trade Center attack. Yet these were not new questions. They had been debated many times during the previous three decades.
Many governments hold relaxed views on whether or not to lock cockpit doors. Most of their air carriers are happy to have selected passengers go on to the flight deck, especially on long flights. It is good for customer relations. Flight crews are generally pleased to explain the intricacies of modern flight to the passengers, especially to children. An argument against open door policies is the ease with which they allow anyone wishing to reach the flight deck and seize control of the aircraft to do so. Carriers decide on their individual policy after assessing the level of threat posed to their services. They, of course, have to meet any regulation dictated by their governments. In America where domestic carriers have had a history of aircraft being seized by Cubans wishing to return to their Caribbean base, policy has always favored the locked door philosophy mandated by