System for latching and locking an aircraft door

A method for unlocking and unlatching a semi-plug type aircraft door, the method comprising:

• when the aircraft door is latched and locked in a closed and a lowered position, driving a configuration change of a lock from a locked configuration where the lock prevents unlatching of the aircraft door to an unlocked configuration where the lock permits unlatching of the aircraft door;
• when the lock is in the unlocked configuration, driving a configuration change of a latch from a latched configuration where the latch interferes with a lift mechanism configured to cause lifting of the aircraft door to permit opening of the aircraft door, to an unlatched configuration where the lift mechanism is permitted to cause lifting of the aircraft door, said lift mechanism comprising at least one crank attached to a lift shaft, the at least one crank coupled to a respective first end of each of two lift rods;
• using an opening movement of a vent flap of the aircraft door to drive the configuration change of the lock;
• using a movement of a handle to cause a rotation of a handle shaft;
• and
• using the rotation of the handle shaft to drive the opening movement of the vent flap,
• wherein:
• a hinge pivotally couples the aircraft door to a fuselage of an aircraft, said hinge being disposed at a lower portion of an opening of the fuselage, the hinge coupled to a respective second end of each of the two lift rods;
• the lift mechanism, through rotation of the at least one crank with the lift shaft driving a movement of the lift rods, provides lifting during an initial opening stage in order to permit door pressure stops attached to the aircraft door to clear and move past corresponding fuselage pressure stops, such that the door pressure stops are free to move outwardly from the fuselage of the aircraft such that the aircraft door is openable by pivotal movement of the aircraft door;
• a clearance between the door pressure stops and the fuselage pressure stops during the initial opening stage is provided by a lifting motion of the aircraft door, and lowering of the aircraft door for closing thereof causes the door pressure stops and the fuselage pressure stops to align such that the door pressure stops rest against the fuselage pressure stops and a pressure differential between an interior and an exterior of the aircraft causes the aircraft door to be securely held via the door pressure stops and the fuselage pressure stops;
• the latch, the lock and the lift rods are disposed within an airstair on an interior side of the aircraft door;
• the method includes actuating the handle to drive the unlocking, the unlatching and the lifting of the aircraft door during the opening of the aircraft door;
• and
• the handle is disposed on a side of the airstair and accessible to a flight crew.

A method for latching and locking a semi-plug type aircraft door, the method comprising:

• when the aircraft door is unlatched and unlocked in a closed and a lowered position, driving a configuration change of a latch from an unlatched configuration where a lift mechanism configured to cause lifting of the aircraft door to permit opening of the aircraft door is permitted to cause lifting of the aircraft door, to a latched configuration where the latch interferes with the lift mechanism, said lift mechanism comprising at least one crank attached to a lift shaft, the at least one crank coupled to a respective first end of each of two lift rods;
• when the latch is in the latched configuration, driving a configuration change of a lock from an unlocked configuration where the lock permits unlatching of the aircraft door to a locked configuration where the lock prevents unlatching of the aircraft door;
• and
• using a closing movement of a vent flap of the aircraft door to drive the configuration change of the lock;
• using a movement of a handle to drive the closing movement of the vent flap,
• wherein:
• a hinge pivotally couples the aircraft door to a fuselage of an aircraft, said hinge being disposed at a lower portion of an opening of the fuselage, the hinge coupled to a respective second end of each of the two lift rods;
• the lift mechanism, through rotation of the at least one crank with the lift shaft driving a movement of the lift rods, provides lifting during an initial opening stage in order to permit door pressure stops attached to the aircraft door to clear and move past corresponding fuselage pressure stops, such that the door pressure stops are free to move outwardly from the fuselage of the aircraft such that the aircraft door is openable by pivotal movement of the aircraft door;
• a clearance between the door pressure stops and the fuselage pressure stops during the initial opening stage is provided by a lifting motion of the aircraft door, and lowering motion of the aircraft door for closing thereof causes the door pressure stops and the fuselage pressure stops to align such that the door pressure stops rest against the fuselage pressure stops and a pressure differential between an interior and an exterior of the aircraft causes the aircraft door to be securely held via the door pressure stops and the fuselage pressure stops;
• the latch, the lock and the lift rods are disposed within an airstair on an interior side of the aircraft door;
• the method includes actuating the handle to drive the lowering, the latching and the locking of the aircraft door during the closing of the aircraft door;
• and
• the handle is disposed on a side of the airstair and accessible to a flight crew.