Definition
The lowest altitude, expressed in feet above mean sea level, to which a pilot may descend while circling to land from an instrument approach. The aircraft must remain at or above the CMDA until in a position from which a normal descent to the runway can be made using normal maneuvers, and the runway environment is in sight.
Plain English
When you fly an instrument approach but need to circle around to line up with a different runway, the CMDA is the floor you can't go below until you're set up to land normally and can see the runway.
Context Anchor
Seen on instrument approach procedures in the circling minimums section, often alongside aircraft approach categories.
Derivation
‘Circling’ describes the maneuver — flying a visual pattern around the airport after completing the instrument approach. ‘Minimum descent altitude’ is the standard term for the lowest altitude allowed on a non-precision approach. Combined, CMDA is the MDA that applies specifically when circling rather than landing straight in.
Why Pilots Care
Maintains required obstacle clearance while maneuvering visually to the runway after the missed approach point.
Intuition Check
“Circling” here does not mean casually flying circles around the airport. It means maneuvering visually near the airport to line up with a runway after completing an instrument approach.
Example Sentence 1
The approach plate showed a CMDA of 1,420 feet for Category B, so we held that altitude as we circled to the opposite runway.
Example Sentence 2
Once the runway environment was in sight below the CMDA, the pilot continued visually to land.