Plain English Meaning

It's a holding-pattern leg you keep flying around and around until you reach a certain altitude. Once you hit that altitude, you stop holding and continue with the rest of the procedure.

Full Definition

An HA leg is a path-and-terminator instrument procedure leg that defines a racetrack-shaped holding pattern flown until a specified altitude is reached. The aircraft continues circling in the published holding pattern until it climbs (or descends) to the altitude that ends the leg, at which point it exits and proceeds on the next leg of the procedure.

Context Anchor

Seen in area navigation instrument procedures and in discussions of path and terminator legs, where the procedure is built from coded segments the can follow.