It’s relatively straight forward to create a flightplan that will enable you the get lateral guidance (left/right of centerline) for a GPS approach. The key is to create a plan that includes a segment overlaying the IF “localizer” for the runway. Then…
- activate that segment
- select GPS in the NAV menu and you’re in business
Simple as that.
Not all runways will include fixes on the “localizer”, so those runways will not be a candidate for a GPS approach.
Here’s a video detailing the process. Note that the segment on the localizer doesn’t need to be full length. You’ll get guidance as long as it’s on the “localizer”, and I recommend that it at least extends to the runway threshold or beyond. If it stops short of the threshold, you’ll stop getting guidance when the flightplan tracker moves off that segment.
I put localizer in quotes when talking about GPS approaches because I think of the localizer as part of a composite signal transmitted from the airport that the aircraft uses for lateral and vertical guidance for an ILS approach. The lateral component of that signal (the localizer) doesn’t exist for GPS. it’s a computed lateral error based on data stored in the GPS receiver and your current location.
My “localizer” in the text above is referring to the extension of the runway you see in the cones.