[img]http://d.yimg.com/a/p/ap/20100219/capt.7cad4426b27346928bda1f6a647cad73.texas_plane_crash_txjp101.jpg?x=82&y=130&q=85&sig=tDy_tHbke00nWdB3ofmJ0w--[/img]AP - After 9/11, cockpit doors were sealed, air marshals were added and airport searches became more aggressive, all to make sure an airliner could never again be used as a weapon. Yet little has been done to guard against attacks with smaller planes.