What is the primary purpose of an altimeter in aviation?

The primary purpose of an altimeter in aviation is to measure altitude. Specifically, it measures the height of an aircraft above a reference point, typically sea level or the ground. Altimeters operate based on changes in atmospheric pressure; as an aircraft climbs, the pressure decreases, and the altimeter reflects this change to indicate the altitude.

Understanding altitude is critical for various aspects of flying, including maintaining safe separation between aircraft, navigating at controlled altitudes, and ensuring compliance with airspace regulations. An accurate altitude reading allows pilots to maintain optimal performance, enhance safety, and respond effectively to changes in weather conditions or air traffic.

Other functions such as monitoring airspeed, determining vertical speed, or providing navigation data are essential in aviation, but they are performed by other instruments. For instance, airspeed is monitored by an airspeed indicator, while vertical speed is measured with a vertical speed indicator. Navigation relies on instruments like GPS or navigation radios rather than an altimeter. Therefore, the altimeter's specialized role in measuring altitude is what defines its primary purpose in aviation.