Definition
A specific geographic point used in an instrument approach procedure that marks a transition or required action — such as where the approach begins, where the final descent starts, or where the missed approach is initiated. Each fix has a published name and is defined by navigation aids, GPS coordinates, or radial/distance from a navaid.
Plain English
A named point in space along an instrument approach that tells the pilot 'something happens here' — start the approach, start descending, or go around if you can't see the runway.
Context Anchor
Seen on instrument approach charts and in arrival procedures. A standard arrival route may lead the aircraft to an instrument approach fix so the approach can begin in an orderly way.
Derivation
Fix' comes from the idea of fixing a position — pinning down exactly where the aircraft is. In navigation, a fix has always meant a confirmed point in space, not a vague area. An 'instrument approach fix' is simply a fix used during an instrument approach procedure.
Why Pilots Care
These fixes keep the aircraft on the correct path and altitude so the approach remains safe and aligned with the runway even in low visibility.
Intuition Check
Do not read fix as “repair.” In this term, a fix is a named location. Also, an instrument approach fix is not the whole approach; it is one point used within the approach or to connect to it.
Example Sentence 1
The STAR ended at the instrument approach fix where we began the published approach into the airport.
Example Sentence 2
ATC cleared the flight to the instrument approach fix to begin the procedure.