An aircraft (1000) includes multiple servicing levels (1014, 1016) and a flight deck level (1040) that is isolated from the servicing levels (1014, 1016). An aircraft security system (1001) includes a passive system (1030) and an active system (1032) that is in operation with said passive system (1030). The passive system (1030) includes a service opening (1050) for both passengers and cargo and the flight deck (1040) that is isolated from the service opening (1050).