Definition of Decision Altitude (DA)
Decision altitude (DA) is a predetermined height depicted in feet MSL (mean sea level) during a precision approach. It indicates the point at which a pilot must initiate a missed approach if the necessary visual references required to continue the approach are not met. DA serves as a vital reference point for pilots to determine whether the aircraft is positioned correctly to safely land. In case the required visual references are not seen, the pilot should execute a missed approach, which is a predetermined maneuver to discontinue the approach and proceed to an assigned altitude or airport. DA varies for different types of approaches and aircraft. It considers various factors such as runway lighting, visibility, terrain, and approach proficiency. The decision altitude is an important element in ensuring the safe landing of the aircraft.
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