Since the September 11, 2001, terrorist attacks on the US, using hijacked planes, reinforced security has crucially included the cockpit — with provisions that are usually redundant. Yet these provisions also created deadly circumstances that abetted Tuesday’s air crash in the southern French Alps.<br /><br /> The revelations about Germanwings suggest that an unbreakable door, button code locking and ignored procedures contributed to its doom. One flight recorder has yielded this conclusion. <br /><br /> Germanwings owner Lufthansa is not one of the companies that require a cabin crew member to temporarily enter the cockpit if one of the pilots steps out — a two-is-better-than-one principle applied by other carriers.<br /><br /> Cockpit locks are designed to be controlled principally from the inside, electronically. <br /><br /> Some critics say keypad entry could endanger cabin crew pressured to reveal them. <br /><br /> An unopposed outsider can get in, but can also be denied entry. <br /><br /> The Germanwings pilot was locked out by the cop
