Originally Posted by BobTurner
Okay, I went out and checked. (Why is this easier when flying than when typing?)
My setup: HX with V6 software (latest), G420W, Trio Pro with GPSS/GPSV, but I suspect HXr and HS and other GPSS autopilots will all be the same.
Starting Point: G420W has an LPV gps approach loaded and activated. GRT has the 420 gps selected as the nav source.
Case 1: If using the gps to navigate along a NoPT route to final, set GRT to GNAV; Set "GPSV Arm" anytime, before or after final course intercept. GRT goes from GNAV to ENAV at intercept if set before, otherwise when you select ARM. (Set it before glide slope intercept or the autopilot will dive the airplane to try to catch it!)
Case 2: If being vectored to final, set GRT autopilot control to "Heading". Use heading bug to set in vectors. Select "GPSV ARM" PRIOR to final course intercept. GRT will automatically go from Heading to Enav at intercept
Case 3: If using gps to navigate to a holding pattern course reversal: Select "GNAV" on GRT. Do NOT select "GPSV ARM" until inbound for the approach. If you need more than the course reversal, e.g., you need to actually hold, do not select ARM until inbound the last time (and you will need to push OBS on the 420W to keep it from sequencing during the hold).
You are correct on all three scenarios and the case #2 will also apply for ILS approaches which are far more likely to be vectored than a typical GPS approach. This method makes flying ILS approach easier than a-walk-in-the-park. What I have learned, NOT to arm it until you have been cleared for the approach. There has been times that I have vectored cross the localizer and if you arm it too soon, the system will sees that an intercept and will try to follow the course.
On other notes, thanks for sharing that the new SW version has been released. Do you know what or how much would be the subscription for the IFR charts and plates?
Looks like one of the new features in the new version is ?Add georeferenced plates, diagrams, sectionals, enroute low, and enroute high charts?