Which step should be taken first when troubleshooting engine abnormalities?

When troubleshooting engine abnormalities, the first step is to verify indications. This process is crucial because it helps ensure that the symptoms you are perceiving—such as unusual engine vibrations, abnormal instrument readings, or other discrepancies—are accurate and not a result of instrument failure or other misleading factors. By confirming that the indications are indeed valid, you create a solid foundation for further troubleshooting.

Verifying indications involves cross-referencing instrument readings and monitoring engine performance closely. If this step is skipped or performed superficially, it may lead to misdiagnosis and potentially unnecessary corrective actions based on incorrect assumptions. Once you have confirmed the accuracy of the indications, you can then proceed to review systems, reference the Pilot Operating Handbook (POH), and assess options for corrective actions with confidence that the issue has been accurately identified.