An assembly includes a first structure having a first pin aperture and at least one first fastener aperture adjacent the first pin aperture and a second structure to attached to the first structure having a second pin aperture and at least one second fastener aperture adjacent the second pin aperture. At least one fastener is configured to pass through the first and second fastener apertures and attach the first structure to the second structure. An assembly pin passes through the first and second pin apertures and is trapped within the first and second pin apertures. A pin-securing washer having a fastener surface defining at least one fastener aperture and a pin-securing surface to secure the assembly pin within the pin apertures. The at least one fastener passes through the at least one fastener aperture of the pin-securing washer.