Definition
On a Standard Instrument Departure (SID) or other instrument procedure, the lowest altitudes a pilot is authorized to fly along a given segment. They are charted to guarantee obstacle clearance, and in some cases to meet ATC, terrain, or airspace requirements. A pilot must be at or above the published minimum altitude for that segment unless ATC issues a different clearance.
Plain English
The lowest height you are allowed to fly on a particular part of a published procedure. Going below it is not permitted unless the controller specifically clears you to do so.
Context Anchor
Seen on instrument departure charts, especially standard instrument departure altitude instructions during the climb after takeoff.
Derivation
Minimum comes from the Latin minimus, meaning “smallest” or “least.” Altitude comes from Latin altus, meaning “high.” Together, the phrase points to the least height allowed in a given part of the procedure.
Why Pilots Care
Observing these altitudes prevents controlled flight into terrain and ensures legal compliance during IFR operations.
Intuition Check
Minimum does not mean “suggested” or “comfortable.” Here it means the lowest altitude permitted for that part of the procedure.
Example Sentence 1
The SID showed a minimum altitude of 3,000 feet until passing the first fix, so the crew leveled there until cleared higher.
Example Sentence 2
The pilot climbed promptly to meet the minimum altitude published for the next leg of the route.