An underwing flap support mounting structure is disclosed that includes an underwing beam comprising an integral clevis at a forward end of the underwing beam and mounted to a lower skin of a wingbox, wherein the integral clevis comprises a first clevis bore and second clevis bore; and a wingbox lug fitting comprising a wingbox lug and a spherical bearing support assembly carrying a race and a spherical bearing, the wingbox lug having a wingbox lug bore and the spherical bearing having a spherical bearing bore, wherein a forward-aft oriented fuse pin is slidably received in the spherical bearing bore, the first clevis bore, and the second clevis bore to inhibit relative linear-vertical motion of the underwing beam and the integral clevis relative to a wingbox lug fitting that is mounted to the lower skin of the wingbox.