An underwing support structure for a flap system of an aircraft, comprising: a plurality of flaps each having a plurality of flap supports (15a, 15b); at least one actuator supported in at least one of the plurality of flap supports (15a, 15b); at least one flap support rib; at least one carrier beam to support one of said plurality of flaps, said carrier beam rotatably engaged in the flap support rib; a tension and compression member engaged to the flap support rib; and a three piece failsafe clevis configured to be connected to a lower surface of a wing and having: a center portion having a center top surface configured to be received on the lower surface, a planar first outer surface and a planar second outer surface, said second outer surface oppositely oriented to the first outer surface, and a channel in which the tension and compression member is received; a left lateral portion connected adjacent the first outer surface and having a planar first inner surface received against the first outer surface and a left top surface coplanar with the center top surface and configured to be received on the lower surface; and a right lateral portion connected adjacent the second outer surface and having a planar second inner surface received against the second outer surface and a right top surface coplanar with the center top surface and configured to be received on the lower surface. a plurality of flaps each having a plurality of flap supports (15a, 15b); at least one actuator supported in at least one of the plurality of flap supports (15a, 15b); at least one flap support rib; at least one carrier beam to support one of said plurality of flaps, said carrier beam rotatably engaged in the flap support rib; a tension and compression member engaged to the flap support rib; and a three piece failsafe clevis configured to be connected to a lower surface of a wing and having: a center portion having a center top surface configured to be received on the lower surface, a planar first outer surface and a planar second outer surface, said second outer surface oppositely oriented to the first outer surface, and a channel in which the tension and compression member is received; a left lateral portion connected adjacent the first outer surface and having a planar first inner surface received against the first outer surface and a left top surface coplanar with the center top surface and configured to be received on the lower surface; and a right lateral portion connected adjacent the second outer surface and having a planar second inner surface received against the second outer surface and a right top surface coplanar with the center top surface and configured to be received on the lower surface. a center portion having a center top surface configured to be received on the lower surface, a planar first outer surface and a planar second outer surface, said second outer surface oppositely oriented to the first outer surface, and a channel in which the tension and compression member is received; a left lateral portion connected adjacent the first outer surface and having a planar first inner surface received against the first outer surface and a left top surface coplanar with the center top surface and configured to be received on the lower surface; and a right lateral portion connected adjacent the second outer surface and having a planar second inner surface received against the second outer surface and a right top surface coplanar with the center top surface and configured to be received on the lower surface.