Abstract: An expandable/collapsible enclosure positioned about the existing door of a flight crew compartment of an airliner, which is expanded either manually or automatically by the motion of the aircraft to form an airlock type enclosure about the door to the flight crew compartment, the enclosure having its own outer secondary door controllable from the flight crew compartment, an individual seeking access to the flight crew compartment having to position themselves in front of the outer door and again within the enclosure for observation by the flight crew personnel before entering the flight crew compartment, the enclosure having chemical or gaseous means for immobilizing an individual not authorized to enter the enclosure or the flight crew compartment who may have overwhelmed a properly identified individual that was authorized to enter the enclosure.

Abstract: An expandable/collapsible enclosure positioned about the existing door to a flight crew compartment of an airliner which is expanded either manually or automatically by the motion of the aircraft to form an airlock type enclosure about the door to the flight crew compartment, the enclosure having its own outer, secondary door controllable from the flight crew compartment, an individual seeking access to the flight crew compartment having to position themselves in front of the outer door and again within the enclosure for observation by the flight crew personnel before entering the flight crew compartment, the enclosure having chemical or gaseous means for immobilizing an individual not authorized to enter the enclosure or the flight crew compartment, who may have overwhelmed the properly identified individual that was authorized to enter the enclosure.