What does an engine run-up check for?

An engine run-up check is designed to assess the operational status and performance of the aircraft's engine and its related systems prior to takeoff. This procedure typically includes testing the engine's performance parameters, such as RPM, and evaluating the functionality of critical systems, which often covers fuel flow, oil pressure, and magneto operation.

During this check, the pilot will often switch between magnetos to ensure that both are functioning properly and that the engine runs smoothly on each independently. Any significant drop in RPM or noticeable discrepancies when switching magnetos can indicate issues that need to be addressed before taking off. The run-up also allows pilots to listen for unusual noises or vibrations that might signify engine trouble.

In contrast, other options like checking only fuel levels, assessing navigation system accuracy, or performing weight and balance calculations do not encompass the full scope of what an engine run-up entails. These tasks are relevant but are performed separately and are not the primary focus of an engine run-up check.