Definition
On an instrument approach chart profile view, the lowest altitude (in feet MSL) at which an aircraft may fly along a specific segment of the approach. It is shown as an underlined number, indicating that the pilot must be at or above that altitude when crossing that point or flying that segment.
Plain English
The lowest height above sea level you are allowed to fly on a particular part of the approach. You can be at this number or higher, but never lower.
Context Anchor
Seen on the profile view of an instrument approach chart, where it shows how low the aircraft may descend during each part of the procedure.
Derivation
Minimum comes from a Latin word meaning “smallest.” Altitude comes from a Latin word meaning “height.” Together, the phrase means the smallest allowed height for that part of the flight.
Why Pilots Care
Descending below the published minimum altitude risks collision with terrain or obstacles and violates instrument flight rules.
Intuition Check
Minimum altitude does not mean “a suggested low target.” It means “do not go lower than this until the procedure or clearance permits it.”
Example Sentence 1
Crossing the final approach fix, the pilot leveled off at the minimum altitude shown on the profile view and continued inbound.
Example Sentence 2
The procedure required maintaining the minimum altitude until the next waypoint to clear the ridge line.