Incident Overview
On June 12, 2019, at approximately 1435 Pacific daylight time, a Cessna 140 airplane, registration N73053, sustained substantial damage during a landing accident near Independence, Oregon. The flight instructor and student pilot were not injured. The airplane was being operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.
Sequence of Events
According to the flight instructor, the accident landing was the second landing of the flight. As the airplane slowed down and began to exit the runway, a loud "clunk" was heard. The airplane then slid sideways, bounced, and ground looped, resulting in substantial damage to the fuselage. The instructor reported that the right wheel assembly had separated at the axle.
Pilot and Aircraft Information
The student pilot, who was also the owner of the airplane, reported purchasing it in April 2019. He had been flying one to three times per week while working toward his private pilot certificate. No issues had been noted during previous flights.
Examination of the Axle
A post-accident examination of the fractured axle assembly revealed that the axle fractured at the transition radius between the longitudinal barrel (tube) portion and the plate portion. A fatigue crack had emanated from multiple origins at the outer surface of the transition radius and extended circumferentially around the outer surface. The fracture features outside the fatigue region showed characteristics consistent with overstress separation. The maintenance history of the landing gear and axle could not be determined.