Engine crankshaft runout is usually checked

Checking engine crankshaft runout is a critical maintenance task that ensures the smooth and efficient performance of the engine. The practice is particularly important during annual inspections because these inspections are comprehensive and designed to review the overall condition and functionality of the aircraft's systems, including the engine. During the annual inspection, mechanics are tasked with measuring various parameters that can affect engine performance and safety, and crankshaft runout is one of the key indicators of an engine's mechanical integrity.

Crankshaft runout refers to the amount of deviation from true center alignment during the rotation of the crankshaft. Excessive runout can lead to uneven wear, increased vibration, and potentially catastrophic failures. As such, it is a standard procedure to evaluate crankshaft runout within the schedule of regular inspections, particularly during the thorough and detailed nature of annual inspections, ensuring any potential issues are identified and rectified before testing and flight operations resume.

While crankshaft runout can indeed be assessed during other maintenance events such as engine overhauls, post-prop strikes, or 100-hour inspections, the systematic approach of annual inspections encompassing a wide array of checks makes it the most suitable option for ensuring ongoing airworthiness and operational safety.