What does the N2 gauge measure?

The N2 gauge measures the rotation speed of the high-speed spool in a jet engine. This high-speed spool is typically associated with the engine's high-pressure turbine and its compressor. Monitoring the N2 speed is crucial for engine performance, as it provides information on how efficiently the engine is operating at various throttle settings.

Understanding the N2 gauge is essential for pilots and engineers because it helps in assessing engine health and performance characteristics. Accurate readings from the N2 gauge assist in managing engine power levels and ensuring safe operation during different flight phases. This makes it a critical instrument in the cockpit, providing vital data needed for effective flight operation.