What is the primary function of an altimeter?

The primary function of an altimeter is to measure altitude above sea level. An altimeter operates based on changes in atmospheric pressure, specifically the decrease in pressure that occurs with an increase in altitude. As an aircraft climbs, the pressure decreases, and the altimeter is calibrated to translate this change into an altitude reading.

This is crucial for pilots as it provides them with vital information needed for safe navigation and operation within controlled airspace. Accurate altitude measurement is essential for maintaining safe separation from terrain and other aircraft, making the altimeter one of the critical instruments in aviation.

While the measurement of atmospheric pressure is part of how an altimeter functions, its main purpose is to indicate altitude, distinguishing it from other instruments that measure airspeed or climb rate. Understanding this function helps pilots make informed decisions regarding their flight profile and altitude adjustments.