Aircraft door hinge assembly
A hinge assembly for attaching a door structure to an aircraft fuselage is provided. The door structure is linked to the aircraft body structure by way of a programmable mechanical linkage that is attached to the hinge member. The programmable mechanical linkage is actuated along the hinge member so as to maintain the door structure attached thereto in a controlled angular relationship relative to the longitudinal axis of the aircraft fuselage through its attachment to the fixed aircraft frame.
1. A hinge assembly for connecting an aircraft door to an aircraft fuselage comprising:
a hinge member having first and second opposed ends, said first end of said hinge member being configured to be coupled to the aircraft fuselage adjacent a door opening;
a door fitting pivotably coupled to said second end of said hinge member, said door fitting being configured to pivot with respect to said hinge member about a first pivot axis, and further being configured to be coupled to the aircraft door; and
a programmable mechanical linkage coupled to said hinge member and to said door fitting, said programmable mechanical linkage being configured to allow said aircraft door to pivot around said second end of said hinge member when said hinge member is moved from a door closed position to a door open position, said programmable mechanical linkage being further configured to cause said aircraft door to rotate and maintain the aircraft door in a generally parallel orientation relative to the longitudinal axis of the aircraft fuselage;
wherein said programmable mechanical linkage includes at least a first pivot fitting, at least a second pivot fitting, at least a first linkage rod, at least a second linkage rod and at least a third linkage rod, and said first pivot fitting, said second pivot fitting, said first linkage rod, said second linkage rod and said third linkage rod are connected in series.
2. The hinge assembly of claim 1 , wherein said hinge member is configured so that when the door structure is moved from the door closed position to the door open position said hinge member is pivoted through the door opening and the door structure is laterally offset from the door opening.
3. The hinge assembly of claim 1 , further comprising an Emergency Power Actuation System (“EPAS”)/snubber cylinder attached between said programmable linkage mechanism and said hinge member so as to drive the door open in an emergency, and to limit the speed of the motion of said hinge member when said hinge member is moved from the door closed position to the door open position.
4. The hinge assembly of claim 1 , wherein at least one of said linkage rods has an adjustable length.
5. The hinge assembly of claim 1 , wherein a first end of said first linkage rod is pivotably coupled to said fuselage, a second end of said first linkage rod is pivotably coupled to a first end of said first pivot fitting, a second end of said first pivot fitting is pivotably coupled to a first end of said second linkage rod, a second end of said second linkage rod is pivotably coupled to a first end of said second pivot fitting, a second end of said second pivot fitting is pivotably coupled to said hinge member, a first end of said third linkage rod is pivotably coupled to said first end of said second pivot fitting, and a second end of said third linkage rod is pivotably coupled to said door fitting.
6. The hinge assembly of claim 5 , wherein said first pivot fitting is pivotably coupled to said hinge member at a point on said first pivot fitting located between said first end of said first pivot fitting and said second end of said first pivot fitting.
7. The hinge assembly of claim 5 , wherein said second end of said second pivot fitting is configured to pivot about a second pivot axis spaced from the first pivot axis.
8. The hinge assembly of claim 3 , wherein a first end of said EPAS/snubber cylinder is pivotably coupled to said hinge member and a second end of said EPAS/snubber cylinder is pivotably coupled to said second pivot fitting.