Aircraft maintenance and repair work is facilitated, especially for a commercial aircraft, by a diagnostic system and method, wherein an aircraft component or assembly of components is monitored by at least one sensor which produces and preferably also stores component status information. A built-in self-test of the link is performed. A cutting wheel is positioned below the turret and is located in a position so as to be in the path of the tips as the turret rotates. A bearing is pivotally disposed within said bearing hole.