Definition
A path and terminator leg type used in RNAV procedure coding in which the aircraft flies a specified course or heading and the leg terminates when the aircraft reaches a specified altitude. The HA code defines a holding pattern leg that ends at an altitude rather than at a fix, distance, or time.
Plain English
A coded segment of a flight procedure that tells the aircraft's navigation system to keep flying until it reaches a particular altitude, then move on to the next part of the procedure.
Context Anchor
Seen in instrument procedure coding, especially in RNAV procedure descriptions that explain how a published path is built in the aircraft’s navigation system.
Derivation
The letter pairs in path-terminator codes follow a convention: the first letter describes the path flown and the second letter describes what ends the leg. In HA, the H comes from 'holding' (the path is a holding pattern) and the A comes from 'altitude' (the leg ends when an altitude is reached).
Why Pilots Care
It guarantees the aircraft attains the altitude needed for obstacle clearance or to join the next segment safely.
Grounding Statement
In an HA leg, the aircraft is not waiting for a clock or a waypoint; it is waiting to reach a specific altitude.
Intuition Check
Do not read “termination” as meaning the whole procedure stops. Here it means this one leg ends when the specified altitude is reached.
Example Sentence 1
The missed approach procedure begins with an HA leg, so the aircraft will continue in the holding pattern until it climbs through 5,000 feet before sequencing to the next fix.
Example Sentence 2
The missed approach includes an HA termination so the aircraft climbs in the hold to the published altitude before proceeding to the hold fix.