Definition
The Minimum Descent Altitude published for a straight-in (non-circling) instrument approach. It is the lowest altitude, expressed in feet MSL, to which a pilot may descend on the final approach segment of a non-precision approach when the runway alignment allows landing without a circling maneuver.
Plain English
The lowest altitude you are allowed to fly down to on a non-precision approach when you are lined up with the runway and not circling to land. You stay at or above this altitude until you can see the runway environment well enough to land.
Context Anchor
Seen in the minimums section of an instrument approach chart and in cold-weather altitude correction discussions.
Derivation
Straight-in' describes an approach aligned with the runway so no turning maneuver is needed before landing. 'MDA' stands for Minimum Descent Altitude. Together, the term names the published floor altitude for that aligned, non-precision approach.
Why Pilots Care
Determines the safe minimum height for continuing the approach to landing while maintaining required obstacle clearance.
Grounding Statement
Think of the Straight-in MDA as the floor for that approach path: do not go below it until you have the runway environment in sight and can continue safely.
Intuition Check
“Straight-in” does not mean any direct route to the airport. Here it means using the published minimums for an approach aligned for landing on the runway, without switching to circling minimums.
Example Sentence 1
On the LOC approach to Runway 27, the straight-in MDA was 880 feet, and we leveled off there until the runway came into sight.
Example Sentence 2
Cold weather corrections must be applied to the straight-in MDA to ensure adequate terrain clearance.