Support pin assembly, support system, and method for the same

A support system for full size determinant assembly of an aircraft structure, the support system comprising:

• an assembly jig;
• a frame section of the aircraft structure for the full size determinant assembly, the frame section positioned on and supported by the assembly jig;
• and
• one or more support pin assemblies coupled to the assembly jig, each support pin assembly comprising:
• a block coupled to the assembly jig, the block having a vertical bore and a horizontal bore intersecting the vertical bore;
• a bushing disposed within the horizontal bore at a first end of the block;
• a barrel nut having a cylindrical body disposed within the vertical bore, the cylindrical body having a barrel nut hole extending transversely through the cylindrical body, the barrel nut hole aligned with the horizontal bore;
• and
• a pin comprising:
• an insertion portion disposed within the bushing;
• an interface element having an interface element first end disposed within the insertion portion and an interface element second end disposed within the barrel nut hole;
• and
• an extending portion extending from the first end of the block, the extending portion having at least one protruding circumferential portion formed on an exterior of the extending portion, the at least one protruding circumferential portion having two or more flat surface portions on opposing sides of the at least one protruding circumferential portion to enable rotation of the pin,
• wherein the at least one protruding circumferential portion on the extending portion of the pin is positioned within a hole in the frame section of the aircraft structure, and provides nominal adjustment of the pin relative to the hole, so that with any occurrence of a binding condition of the pin within the hole, the pin is released from the binding condition by rotating the pin via the two or more flat surface portions.

A method of supporting an aircraft structure for full size determinant assembly, the method comprising:

• coupling one or more support pin assemblies to an assembly jig, each support pin assembly comprising:
• a block having a vertical bore and a horizontal bore intersecting the vertical bore, wherein the block is coupled to the assembly jig;
• a bushing disposed within the horizontal bore at a first end of the block;
• a barrel nut having a cylindrical body disposed within the vertical bore, the cylindrical body having a barrel nut hole extending transversely through the cylindrical body, the barrel nut hole aligned with the horizontal bore;
• and
• a pin comprising:
• an insertion portion disposed within the bushing;
• an interface element having an interface element first end disposed within the insertion portion and an interface element second end disposed within the barrel nut hole;
• and
• an extending portion extending from the first end of the block, the extending portion having at least one protruding circumferential portion formed on an exterior of the extending portion, the at least one protruding circumferential portion having two or more flat surface portions on opposing sides of the at least one protruding circumferential portion to enable rotation of the pin;
• positioning and supporting a frame section of the aircraft structure for the full size determinant assembly on the assembly jig;
• and
• positioning the at least one protruding circumferential portion on the extending portion of the pin of one of the one or more support pin assemblies within a hole in the frame section of the aircraft structure, to provide nominal adjustment of the pin relative to the hole, so that with any occurrence of a binding condition of the pin within the hole, the pin is released from the binding condition by rotating the pin via the two or more flat surface portions.