Self-aligning fitting assemblies and systems and methods including the same

A method of assembling an airframe, the method comprising:

• translating a floor grid relative to a fuselage barrel to operatively locate the floor grid within the fuselage barrel, wherein the floor grid is operatively attached to a plurality of floor-side fittings that includes a plurality of floor-side attachment holes, and further wherein the fuselage barrel is operatively attached to a plurality of barrel-side fittings that includes a plurality of barrel-side attachment holes;
• operatively aligning a plurality of alignment pin recesses with a corresponding plurality of fitting alignment recesses, wherein the plurality of alignment pin recesses is formed within one of the plurality of floor-side fittings and the plurality of barrel-side fittings, and further wherein the plurality of fitting alignment recesses is formed within the other of the plurality of floor-side fittings and the plurality of barrel-side fittings;
• locating a plurality of alignment pins within the plurality of alignment pin recesses, wherein the plurality of alignment pins includes a plurality of alignment surfaces, and further wherein the locating includes extending the plurality of alignment surfaces through respective fitting alignment recesses of the plurality of fitting alignment recesses;
• lowering the floor grid relative to the fuselage barrel to translate the plurality of barrel-side fittings and the plurality of floor-side fittings relative to one another from a first orientation, in which the plurality of floor-side attachment holes is not aligned with the plurality of barrel-side attachment holes, to a second orientation, in which each of the plurality of floor-side attachment holes is at least partially aligned with a corresponding barrel-side attachment hole of the plurality of barrel-side attachment holes, wherein the plurality of fitting alignment recesses is shaped to direct the plurality of floor-side fittings and the plurality of barrel-side fittings toward the second orientation during the lowering;
• and
• installing a plurality of fasteners within the airframe by extending each of the plurality of fasteners through a selected one of the plurality of barrel-side attachment holes and also through a corresponding one of the plurality of floor-side attachment holes.