Definition
An RNAV path-terminator leg that defines a holding pattern at a specified fix, which the aircraft continues to fly until the pilot manually terminates it, typically when cleared by ATC to leave the hold and proceed on course.
Plain English
A coded holding pattern in the flight plan that keeps you circling the fix until the pilot decides — usually after an ATC clearance — to break out and continue.
Context Anchor
Seen in instrument procedure coding and navigation-system behavior for RNAV procedures, especially where a published hold is part of an approach or missed approach path.
Derivation
The two-letter codes used for RNAV legs come from ARINC 424, the industry standard for coding navigation database paths. 'H' identifies the leg as a hold; the second letter says how the hold ends. 'M' stands for Manual — the pilot ends it by hand. Other hold codes use 'F' (single circuit, then continue) or 'A' (until reaching an altitude).
Why Pilots Care
Allows flexible delay or sequencing without a fixed time or distance limit, keeping the aircraft in protected airspace until cleared to proceed.
Grounding Statement
Picture the aircraft flying the racetrack-shaped hold repeatedly until the pilot tells the navigation system, “continue now.”
Intuition Check
Do not read “leg” as an ordinary body part; here it means one coded segment of a flight procedure. Do not assume an HM leg ends on its own; HM specifically means the pilot must manually terminate it.
Example Sentence 1
After the missed approach, the procedure coded an HM leg at the holding fix, so the crew remained in the hold until ATC cleared them for another approach.
Example Sentence 2
After entering the HM leg the crew remained in the hold until ATC issued further clearance.