Which type of altitude directly affects how pilots control their altitude readings?

Indicated altitude is the reading displayed on the altimeter, which is directly affected by the current atmospheric pressure settings. Pilots rely on the indicated altitude to maintain safety and proper flight levels as it reflects how high the aircraft is relative to a predefined reference level, usually sea level, based on the local atmospheric pressure.

The altimeter measures the atmospheric pressure and translates it into altitude. If the pressure changes, pilots must adjust the altimeter setting to ensure that the indicated altitude remains accurate. This is particularly important when flying in varying weather conditions or when changing altimeter settings at different airfields. Therefore, the indicated altitude is crucial for pilots during flight operations, as it informs them about their real-time altitude in relation to the surrounding airspace standards.