What is the primary function of the altimeter in an aircraft?

The primary function of the altimeter in an aircraft is to determine altitude. An altimeter measures the atmospheric pressure outside the aircraft and converts that pressure into an altitude reading based on the standard atmosphere. This reading is crucial for pilots as it helps them maintain safe flight levels and avoid terrain. It ensures the aircraft operates at the designated altitudes for both safety and airspace management. Pilots rely on this information during takeoff, landing, and while cruising, allowing for effective navigation and adherence to air traffic control instructions.

While other instruments may track vertical velocity or assess engine performance, they do not serve the same role as the altimeter, which specifically focuses on altitude measurement.