What role does the altimeter play in an aircraft?

The altimeter plays a crucial role in an aircraft by measuring altitude based on atmospheric pressure. This instrument works on the principle that atmospheric pressure decreases as altitude increases. The altimeter uses a barometric pressure sensor to compare the current air pressure outside the aircraft with a standard pressure level. As the aircraft climbs or descends, changes in atmospheric pressure are translated into altitude readings, allowing pilots to gauge their height above sea level.

This function is essential for safe navigation and operation, especially in controlled airspace and when flying in various weather conditions. Having accurate altitude information helps pilots maintain safe separation from terrain and other aircraft.