Avionic door lock system

Abstract

A security system adapted for use on an aircraft to prevent unauthorized access into a cockpit area of the aircraft via a cockpit door. The system includes a keypad accessible by individuals in a cabin area of the aircraft. A logic system is in communication with the keypad and also with a switch disposed inside the cockpit. Occupants of the cockpit, via the switch, have the ability to manually unlock the cockpit door, to deny the request for entry, or to do nothing, in which case the door will be automatically unlocked after the expiration of a predetermined time interval. No amount of tampering with the keypad or destruction of the keypad can unlock the cockpit door if the cockpit occupants decide to deny a request for entry via appropriate positioning of the switch. A pressure sensor in communication with the controller allows the door to be automatically unlocked in the event of a decompression condition occurring in the cockpit.

What is claimed is:  
     
         1 . A security system for preventing unauthorized access to a control center of a mobile platform, wherein the control center is separated from a passenger area of said mobile platform by a door; said system comprising: 
 a lock for locking said door;    a user input device accessible by individuals in said passenger area to input a predetermined access code to request unlocking of said door;    a controller responsive to said user input device for producing a signal within said control center when said access code is entered that entry to said control center has been requested by an individual within said passenger area; and    a control device within said passenger area in communication with said lock for allowing an individual in the control center to unlock said door.    
     
     
         2 . The system of  claim 1 , wherein: 
 said control device is in communication with said controller;    wherein said controller is in communication with said lock; and    wherein said control device commands said controller to unlock said lock.    
     
     
         3 . The system of  claim 1 , wherein said control device comprises a switch for allowing said lock to be immediately unlocked.  
     
     
         4 . The system of  claim 2 , wherein said control device comprises a switch having a position signaling said controller to unlock said lock after a predetermined time delay period has expired.  
     
     
         5 . The system of  claim 2 , wherein said control device comprises a switch for signaling said controller to ignore said request for entry and to maintain said lock in a locked position.  
     
     
         6 . A security system for preventing unauthorized access to a cockpit of an aircraft, wherein the cockpit is separated from a cabin area by a cockpit door, the system comprising: 
 a lock for locking the door in a closed position;    a user input device for allowing an individual in said cabin area to input a predetermined access code to request unlocking of the cockpit door;    a controller responsive to said user input device for producing a signal when said access code is entered that entry to the cockpit has been requested; and    a switch in communication with said lock for allowing an individual in the cockpit to unlock said door.    
     
     
         7 . The security system of  claim 6 , wherein said lock is responsive to said controller and said controller is responsive to said switch; and 
 wherein said controller commands said lock to an unlocked position a predetermined delay time after said access code is entered at said user input device.    
     
     
         8 . The security system of  claim 6 , wherein said controller comprises a chime that produces an audible signal when said access code is entered at said user input device.  
     
     
         9 . The security system of  claim 6 , wherein said switch comprises a multi-position switch in communication with said controller for enabling an individual on said cockpit to deny access to said cockpit and inhibit operation of said user input device for a predetermined time period after said access code had been entered at said user input device.  
     
     
         10 . The security system of  claim 6 , wherein said switch is in communication with said controller and comprises a multi-position switch including: 
 a first position in which said switch signals said controller to unlock said lock when said predetermined delay time has expired;    a second position, in which said switch signals said controller to immediately unlock said lock; and    a third position in which said switch signals said controller to maintain said lock in said locked position and to disable said user input device for said predetermined time period.    
     
     
         11 . The security system of  claim 10 , further comprising: 
 a chime responsive to said controller for producing an audible signal in said cockpit when said individual in said cabin area has input said access code into said user input device.    
     
     
         12 . The security system of  claim 10 , further comprising: 
 an indicator light responsive to said controller for providing a visual indication to an individual on said cockpit that an individual in said cabin area has requested access to said cockpit via said user input device.    
     
     
         13 . The system of  claim 6 , wherein said user input device comprises a keypad.  
     
     
         14 . The system of  claim 13 , wherein said keypad comprises: 
 a first indicator light indicating that said cockpit door is in said locked position;    a second indicator light indicating that said access code has been received by said controller; and    a third indicator light indicating that said lock has been moved to said unlocked position.    
     
     
         15 . A security system for preventing unauthorized access to a cockpit of an aircraft, wherein the cockpit is separated from a cabin area by a cockpit door, the system comprising: 
 a lock for locking the door in a closed position;    a user keypad for allowing an individual in said cabin area to input a predetermined access code to request unlocking of the cockpit door;    a controller responsive to said user input device for producing a signal detectable in said cockpit when said access code is entered that entry to the cockpit has been requested;    a switch in communication with said controller for allowing an individual in the cockpit to select an action including: 
 commanding said controller to immediately unlock said lock; and  
 commanding said controller to ignore a previous request by said individual, via said keypad, for access to said cockpit and to maintain said lock in a locked position.  
   
     
     
         16 . The system of  claim 15 , wherein said switch includes an automatic response position which signals said controller to automatically unlock said lock after a predetermined time delay period has expired after said access code has been input into said keypad.  
     
     
         17 . The system of  claim 15 , wherein said predetermined time delay period includes at least: 
 a first delay interval which commences when said signal is generated that said access code has been entered in said keypad; and    a second delay interval during which said controller produces a second signal signaling to said occupants of said cockpit that said controller will automatically unlock said lock at an expiration of said first delay interval.    
     
     
         18 . The system of  claim 15 , wherein said predetermined time delay period includes: 
 a first delay interval which commences when said signal is generated that said access code has been entered in said keypad;    a second delay interval which commences upon the expiration of said first delay interval, said controller generating a second signal at a beginning of said second delay interval reminding occupants of said cockpit that cockpit door has not been unlocked or said request for entry denied via said switch; and    a third delay interval during which said controller produces a third signal signaling to said occupants of said cockpit that said controller will automatically unlock said lock at an expiration of said third delay interval.    
     
     
         19 . The system of  claim 15 , wherein said keypad comprises: 
 a first indicator light for indicating that said lock is in a locked condition; and    a second indicator light for indicating that said lock has been moved into an unlocked condition.    
     
     
         20 . The system of  claim 15 , wherein said keypad comprises: 
 a first indicator light for indicating that said lock is in a locked condition;    a second indicator light for indicating that said lock has been moved into an unlocked condition; and    a third indicator light for indicating that said access code has been received by said controller and that said occupants in said cockpit have been apprised of said request for entry to said cockpit.    
     
     
         21 . The system of  claim 15 , wherein said signal comprises an audible signal generated by a chime, and wherein said chime is in communication with said controller.  
     
     
         22 . The system of  claim 15 , wherein said controller operates to inhibit further requests for entry to said cockpit for a predetermined delay interval if said switch is positioned to command said controller to ignore said previous request for entry to said cockpit.  
     
     
         23 . A method for securing a control center of a mobile platform from unauthorized entry, wherein the mobile platform includes a door separating said control center from a passenger area, the method comprising: 
 using a lock to lock said door in a closed position;    using a user input device to allow an individual in said passenger area to input an access code to request entry to said control center;    using a controller to receive said request for entry and to provide a signal to an occupant in said control center that a request for entry to said control center has been made;    using a control device for allowing said occupant to perform at least one action including: 
 immediately unlocking said lock; and  
 unlocking said lock only after the expiration of a predetermined time delay interval.