What is the recommended reference for crankshaft runout tolerance?

The recommended reference for crankshaft runout tolerance is the current manufacturer's maintenance instructions. These instructions provide the most accurate and specific standards set by the manufacturer, which is crucial for ensuring the safety, reliability, and performance of the engine. Manufacturer maintenance instructions include tolerances that have been tested and validated through the design and testing phases, making them the authoritative source that technicians should rely on for determining proper specifications.

In contrast, Airworthiness Directives generally address broader safety issues and might not contain specific runout tolerances. Service Bulletins can provide updates or recommendations but may not contain the detailed specifications needed for maintenance tasks. The Pilot Operating Handbook primarily focuses on operational guidelines and limitations for pilots, rather than specific mechanical tolerances or maintenance procedures. Thus, the manufacturer's maintenance instructions are essential for accurate compliance with standards needed for crankshaft maintenance.