Incident Overview
A pilot reported that during the landing rollout, after applying the brakes, the left wheel separated from the main landing gear. The aircraft subsequently veered off the left side of the runway.
Aircraft Configuration
The aircraft was equipped with a snow-ski adapter kit, which had been installed on November 20, 1972.
Mechanical Failure Details
Examination determined that the four-wheel assembly retention bolts had sheared off upon landing touchdown. The upper two bolts failed first, after which the nuts were stripped off from the lower two bolts. This resulted in the left landing gear wheel assembly separating from the landing gear strut.
Inspection Findings
Research conducted after the incident revealed that there is no inspection criteria specified for inspecting the wheel assembly retention bolts.
Conclusion
The wheel separation occurred due to the shearing of the retention bolts and stripping of the nuts. No inspection criteria existed for these bolts at the time.