Accident Overview
A commercial pilot was landing a tricycle gear-equipped airplane on a gravel-surfaced runway. During the landing roll, one side of the nose gear wheel flange partially separated from the wheel hub. The nose wheel flange dug into the runway surface, causing the airplane to nose over. The accident resulted in damage to the wings, fuselage, and empennage.
Wheel Assembly Details
The airplane was equipped with a McCauley nose wheel assembly fitted with a 600×6 tire. The wheel flange consists of two halves bolted together on either side of the wheel hub assembly. Each side is secured with six hex-head bolts threaded into the hub. The bolts are required to be torqued to 200 inch-pounds and are not equipped with any lock-washers.
Investigative Findings
An FAA inspector traveled to both the departure airport and the arrival airport. At the departure airport, the inspector located one wheel flange bolt along the accident airplane's taxi path to the runway. The bolt and its threads were undamaged. At the destination airport, another wheel flange bolt was found. That bolt was sheared.
Damage Assessment
The airplane sustained structural damage to the wings, fuselage, and empennage as a result of the nose-over.