Definition
A geographic point on an instrument approach procedure or departure procedure that defines where the aircraft is required to begin a turn to a new course. The turn fix is identified by a navigation aid, intersection, DME distance, radial crossing, or waypoint, and is published on the approach or departure chart.
Plain English
A specific point in the sky where the chart tells you to start turning to your next heading.
Context Anchor
Seen on instrument approach, departure, and route charts where a planned course change is shown at a specific point.
Derivation
From 'fix' meaning a definite, established position determined by navigation references. A turn fix is simply a fix whose purpose is to mark where a turn begins.
Why Pilots Care
Missing the turn at the correct point can cause course deviation, airspace incursion, or failure to meet a crossing restriction.
Analogy
It is like an intersection on a road: you do not turn just because the road will eventually change direction; you turn at the marked place.
Intuition Check
A turn fix is not something that “fixes” a turn. It is the specific charted point where the turn is made.
Example Sentence 1
Approaching the turn fix, the pilot began the procedure turn outbound as charted.
Example Sentence 2
ATC instructed the pilot to proceed direct to the turn fix before descending.