Abstract: A warning indication system and method of using the same in conjunction with a cargo door of an aircraft. The cargo door is positionable in an opened position; a closed position; a closed and latched position; and a closed, latched, and locked position. The method includes outputting first and second closed signals when the cargo door is in the closed position; outputting first and second latched signals when the cargo door is in the closed and latched position; and outputting first and second locked signals when the cargo door is in the closed, latched, and locked position. All of the signals are then analyzed to positively determine the position of the cargo door, while minimizing the probability of false indications. Various warnings are generated in response to the combination of signals received. The apparatus employs a dual logic system and redundant sensors to provide differing warnings dependent on the phase of flight.

Abstract: A warning indication system and method of using the same in conjunction with a cargo door of an aircraft. The cargo door is positionable in an opened position; a closed position; a closed and latched position; and a closed, latched, and locked position. The method includes outputting first and second closed signals when the cargo door is in the closed position; outputting first and second latched signals when the cargo door is in the closed and latched position; and outputting first and second locked signals when the cargo door is in the closed, latched, and locked position. All of the signals are then analyzed to positively determine the position of the cargo door, while minimizing the probability of false indications. Various warnings are generated in response to the combination of signals received. The apparatus employs a dual logic system and redundant sensors to provide differing warnings dependent on the phase of flight.

Abstract: An aircraft locking system (11) is provided that avoids inadvertent or deliberate operation of an aircraft exit opening means (50) during take-off roll, in-flight, or during landing. The aircraft locking system includes means for determining whether engines of the aircraft are running (12), means for determining thrust lever position (14), means for determining whether the aircraft is in an air mode or a ground mode (16), and means for determining whether a predetermined number of service/entry doors are closed (18). Means for generating a lock/unlock signal (32, 40) are responsive to the engine running determining means, the thrust lever position determining means, and the service/entry door-closed determining means.