Definition
Instrument approach procedures that are designed and titled specifically for use with GPS as the primary navigation source, independent of any ground-based navigation aid such as a VOR, NDB, or localizer. The approach chart is titled with 'GPS' or 'RNAV (GPS)' in the procedure name, and the entire approach -- from the initial approach fix through the missed approach -- is flown using GPS guidance.
Plain English
An instrument approach that is built to be flown using GPS only. The pilot does not need to tune or back up the procedure with a ground-based navigation station. GPS handles every part of it, from joining the approach to flying the missed approach.
Context Anchor
Seen when studying or briefing GPS instrument approaches, especially when choosing the correct published approach from the aircraft’s GPS database.
Derivation
Stand-alone' means it stands on its own -- it does not lean on another navigation system to work. The approach is complete in itself using GPS.
Why Pilots Care
They allow safe instrument landings at airports that lack traditional ground-based navigation systems such as ILS.
Intuition Check
Do not assume “stand-alone” means “use any GPS however you want.” It means the published approach itself is designed for GPS, and the pilot still must use approved equipment and the correct database procedure.
Example Sentence 1
Because the airport had no VOR or ILS, the pilot planned a GPS stand-alone approach to runway 27.
Example Sentence 2
During the checkride the examiner asked for a GPS stand-alone approach to demonstrate satellite-only navigation skills.