Plain English Meaning
How high above the airport you are when you reach the lowest altitude allowed during a circling approach. It tells you, in feet, how far above the airport the bottom of your descent sits.
Full Definition
The vertical distance, expressed in feet, between the Minimum Descent Altitude (MDA) on a circling instrument approach and the published airport elevation. HAA is published on instrument approach charts for circling minimums.
Context Anchor
Seen in the minimums area of instrument approach information, including radar approach examples, especially where circling minimums are shown.