Plain English Meaning

These are the start-of-final-approach points the flight computer keeps on file, with one for each kind of navigation system the aircraft might use to fly the approach.

Full Definition

Sensor final approach fixes are the specific points, defined for each navigation sensor type (such as GPS, VOR, or ILS), that the Flight Management System (FMS) recognizes as the start of the final approach segment for that sensor. Because each sensor source can place the final approach fix at a slightly different geographic , the FMS stores a separate for each sensor type used in the .