Definition
A published altitude that ensures safe terrain and obstacle clearance during a turn at certain en route fixes or NAVAIDs, where the standard minimum en route altitude does not provide adequate clearance for the larger area an aircraft sweeps through during a turn.
Plain English
When you turn at a fix, your aircraft swings through a wider piece of sky than when flying straight. At some fixes, that extra space contains terrain or obstacles. Minimum turning altitude is the higher altitude you must be at to safely complete that turn.
Context Anchor
Seen on instrument procedures and route segments where a turn at a named point needs extra altitude for safe clearance.
Why Pilots Care
Provides the extra margin needed for obstacle clearance when standard altitudes would leave insufficient room during the turn.
Grounding Statement
Picture approaching a required turn in instrument conditions: the minimum turning altitude tells you how high you must be before starting that turn safely.
Intuition Check
Do not read “minimum” as a suggested or comfortable altitude. Here it means the lowest permitted altitude for starting the turn while still meeting obstacle-clearance requirements.
Example Sentence 1
Approaching the fix, the crew climbed to 11,400 feet to meet the published minimum turning altitude before beginning the right turn on course.
Example Sentence 2
The chart showed a minimum turning altitude of 6200 feet to protect the aircraft during the course reversal.