What happened
The pilot was conducting a practice maneuver involving a touch-and-go landing when the incident occurred. During his second attempt at this procedure, he noted that the aircraft was positioned slightly high on the final approach segment. To correct for the altitude and ensure a safe stop within the available runway length, he reduced engine power to execute a short field landing technique.
The aircraft touched down on the sod surface in a flat attitude. The impact was described as moderate but sufficient to compromise the landing gear structure. Immediately upon touchdown, the nose gear axle sheared off. With the forward support lost, the nose gear assembly dug into the ground, causing the aircraft to rotate forward and come to rest on its nose.
The investigation
The physical evidence indicated that the primary mechanical failure was the shear of the nose gear axle. This structural failure occurred as a direct result of the forces generated during the landing impact. The subsequent nosing over was caused by the nose gear collapsing into the soft sod surface after the axle failed.