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 point, the FMS stores a separate FAF for each sensor type used in the procedure.
Plain English
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.
Context Anchor
Seen when reviewing or loading an RNAV or computer-based instrument approach and checking that the fixes in the navigation system match the published procedure.
Derivation
FAF comes from final approach fix. “Final” means the last part, “approach” means moving toward the runway or airport, and a “fix” is a known position. Together, the term means the known point that starts the last part of the approach.
Why Pilots Care
They let pilots know exactly when to begin the final descent using modern equipment, keeping the approach safe and on course.
Intuition Check
A sensor FAF is not just any fix near the airport. It is the specific final-approach-start point used by the navigation system for that procedure.
Example Sentence 1
When the crew switched the approach from GPS to ILS, the FMS automatically used a different sensor final approach fix for sequencing.
Example Sentence 2
Sensor final approach fixes appear on the approach plate with GPS-specific symbols.