The Marine Corps' external study on F-35 sustainment will focus on long-term maintenance and spare parts inventory, according to a service official. Lt. Gen. Steven Rudder, deputy commandant for aviation, told reporters Nov. 9 it's common for the Marine Corps to conduct readiness reviews of its airframes. "Most of it is in conjunction with the [F-35 program office], . . . with what the Navy is doing," he said following a House Armed Services readiness subcommittee hearing. "Think about where...