On May 19, 2013, about 1130 Alaska daylight time, a tundra-tire and tailwheel-equipped Maule M-6-235 airplane, N56464, sustained substantial damage while landing at the Goose Bay Airport, about 9 miles south of Big Lake, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) personal flight under the provisions of Title 14, CFR Part 91, when the accident occurred. The airline transport pilot was not injured. Visual meteorological conditions prevailed and a VFR military flight plan had been filed. The flight departed Elmendorf Air Force Base about 0830. During a telephone conversation with the National Transportation Safety Board investigator-in-charge (NTSB) on May 19, the pilot stated that he was practicing stop-and-go landings on the gravel covered runway at the Goose Bay Airport. Upon touchdown, the right main gear separated at the axle housing, which pivoted the airplane to the right as the main landing gear leg dug into the gravel covered runway. The airplane subsequently nosed down, coming to rest on the propeller spinner and left wing. The airplane sustained substantial damage to the left wing and lift struts. The pilot noted that the airplane was equipped with 35-inch tundra tires. A postaccident examination, by the pilot, revealed the right main landing gear axle separated at the axle housing to main landing gear leg attach point. A Senior Safety Board Metallurgist reported that visual and magnified optical examination of the fractured surfaces revealed features consistent with a bending overstress fracture. (A synopsis of the NTSB Metallurgist's case review is included in the public docket for this accident.)