What happened
During the landing roll, the pilot reported that the aircraft remained on all three wheels before the tailwheel failed. The failure caused the tailwheel to steer sideways, resulting in the aircraft veering off the runway.
The investigation
An examination of the wreckage revealed that the tailwheel truss axle had failed. Further inspection showed that 50% of the fracture surface was rusted. Records indicated the aircraft had received a Phase 3 inspection under the company's progressive maintenance program 26 flight hours prior to the accident. This phase inspection required inspection and retraction testing of the landing gear system.
Findings
Company personnel stated that inspection of the truss axle was not accomplished during the previous maintenance event.