What happened
Upon touchdown, the pilot reported that the airplane felt as though it had a flat tire and began pulling sharply to the right. Following this sensation, the aircraft exited the runway surface. During the excursion, the landing gear collapsed, though the airplane eventually came to a stop in an upright position.
The investigation
An examination of the landing gear identified that the inboard half of the right main landing gear wheel had sustained a fracture through approximately 120 degrees of the flange.
Technical analysis of the fracture surface was conducted at the NTSB Materials Laboratory in Washington, D.C. The examination revealed striations, crack arrest positions, and ratchet marks, which are characteristic features of fatigue propagation. Investigators were unable to determine the specific origin of the fatigue because rubber deposits were present on the fracture surface.