FAA Powerplant Written Practice Test

What publication provides crankshaft runout tolerances after a ground incident involving a propeller sudden stoppage?

1. Airworthiness directives

2. Manufacturer's maintenance instructions

3. Federal Aviation Regulations

4. Service bulletins

The correct answer is: Manufacturer's maintenance instructions

The correct choice is the manufacturer's maintenance instructions. These instructions typically provide detailed information specific to a particular aircraft or engine model, including maintenance procedures, troubleshooting, and tolerances. When an incident involves a propeller sudden stoppage, the manufacturer’s maintenance instructions will outline the steps necessary to assess the engine's condition, including allowed crankshaft runout tolerances. This information is critical for determining whether the engine remains airworthy after such an event. In contrast, although airworthiness directives might provide important safety information and mandatory compliance actions, they generally do not focus on specific technical tolerances for components based on an incident. Federal Aviation Regulations outline the legal framework for aviation operations and maintenance standards but lack the specific technical details. Service bulletins provide updates and recommendations from the manufacturer but may not cover all operational procedures or tolerances required after a specific incident. Thus, the manufacturer’s maintenance instructions are the most reliable source for crankshaft runout tolerances following the described scenario.