How do pilots use the tachometer?

Pilots use the tachometer primarily to monitor engine RPM, which is essential for ensuring the engine operates within its optimal range for performance and safety. The tachometer provides a visual indication of the engine's rotational speed in revolutions per minute (RPM).

Monitoring engine RPM is crucial during various phases of flight, such as takeoff, climb, cruise, and landing. It helps pilots make informed decisions about throttle management, ascent and descent rates, and maintaining engine efficiency, particularly in piston engine aircraft where the engine's performance directly affects aircraft handling and safety.

In contrast, tracking flight duration pertains more to a timekeeping instrument rather than the tachometer's function, altitude changes are measured using altimeters, and fuel efficiency assessments generally rely on fuel flow instruments rather than engine RPM alone. Thus, the tachometer's primary role is linked to monitoring the engine's performance through RPM, making this understanding vital for both flight operations and overall aircraft management.