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Old 03-14-2014, 04:33 PM
BobTurner BobTurner is offline
Join Date: Dec 2011
Location: Livermore, CA
Posts: 7,351
Default When to push "GPSV ARM"

Originally Posted by BobTurner View Post
While inbound for the approach, have LNAV set to GNAV (so it will do turn anticipation). Once on final, the HXr will automatically switch to ENAV. If you push "missed" it will go back to GNAV.
I have the newest software and that's how mine works. Arm the approach anytime, it switches when on final.

Edit: I should go check wrt the holding pattern behavior, I fly so few, you may be right there. It must be in GNAV to do the holding pattern, as you say.
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).
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