What is a crucial point to check during a 100-hour inspection?

During a 100-hour inspection, checking cylinder compression is crucial because it directly affects the engine's performance and reliability. The compression in each cylinder indicates the engine's ability to generate power and operate efficiently. Low compression can lead to poor engine performance, increased fuel consumption, and potentially catastrophic engine failure if not addressed.

This inspection ensures optimal engine operation by identifying any issues related to the piston rings, valves, or gaskets. Detecting problems at this stage can prevent further damage and costly repairs later on. While items like fuel filters, airframe structural integrity, and landing gear inspection are also important in aircraft maintenance, the cylinder compression check is specifically vital for confirming that the engine is in good working condition, thus directly impacting flight safety.