What is Decision Height (DH) in aviation?

Decision Height (DH) is specifically defined as the height above the touchdown zone on a runway where a pilot must decide whether to land or execute a missed approach. This altitude is a critical reference point during an instrument approach to ensure that the pilot has sufficient visibility and conditions to safely complete the landing. If the pilot is unable to see the required visual references at or above this height, protocol dictates that they must initiate a go-around or missed approach to ensure safety.

In aviation procedures, understanding DH is vital for maintaining safety during low visibility conditions, as it directly impacts the decision-making process when approaching a runway. It provides a definitive altitude that triggers action, ensuring pilots are prepared and adequately informed for the final stages of landing.