Hi there, if I selected the INS+GPS option in the PFB, if I just modify my GPS approaach will the auto pilot using the INS button follow the GPS approach procedure?

1 hour ago, YS0430 said:

Hi there, if I selected the INS+GPS option in the PFB, if I just modify my GPS approaach will the auto pilot using the INS button follow the GPS approach procedure?

No, for AP to follow the GPS on approach, one needs to select RADIO on the INS/RADIO button, AND select VOR not INS as well. Also, as is routine on the GNS530, select GPS or NAV on the GNS, as required for the type of approach. Good idea also to tune all 3 NAV radios to the frequency, if flying an ILS, LOC or VOR approach type.

19 hours ago, Nikita2024 said:

No, for AP to follow the GPS on approach, one needs to select RADIO on the INS/RADIO button, AND select VOR not INS as well. Also, as is routine on the GNS530, select GPS or NAV on the GNS, as required for the type of approach. Good idea also to tune all 3 NAV radios to the frequency, if flying an ILS, LOC or VOR approach type.

feels quite complicated to me 🙂

3 hours ago, YS0430 said:

feels quite complicated to me 🙂

This is a complicated model of a complex aircraft. Did you try using the GPS for an approach yet? How did it go for you?

On 5/7/2026 at 1:01 PM, Nikita2024 said:

No, for AP to follow the GPS on approach, one needs to select RADIO on the INS/RADIO button, AND select VOR not INS as well. Also, as is routine on the GNS530, select GPS or NAV on the GNS, as required for the type of approach. Good idea also to tune all 3 NAV radios to the frequency, if flying an ILS, LOC or VOR approach type.

Wait a sec. If this is true, then how does one change from GPS enroute NAV to an ILS approach if BOTH use the "radio" selection? How does it know whether to follow the nav radios or the GPS? How would it know when to switch from one to the other just by changing from "VOR" to "LOC"? What displays on the HSI when both a tuned VOR AND a GPS route are loaded? Which distance and time values are displayed?

Edited 8 hours ago8 hr by Joshua Green

1 hour ago, Joshua Green said:

Wait a sec. If this is true, then how does one change from GPS enroute NAV to an ILS approach if BOTH use the "radio" selection? How does it know whether to follow the nav radios or the GPS? How would it know when to switch from one to the other just by changing from "VOR" to "LOC"? What displays on the HSI when both a tuned VOR AND a GPS route are loaded? Which distance and time values are displayed?

Let's back up a bit. To navigate using the GNS530, one has to select RADIO and VOR in the AFCS. Then to navigate by GPS, press CDI on the GNS530 to select GPS.

To navigate by VOR, LOC or ILS; press CDI on the GNS530 to select VLOC. This is the same thing as pressing GPS/NAV in MSFS, but put that aside for the L-1011.

For example: I'm navigating by INS enroute through a standard arrival (STAR). Near the last STAR waypoints, I want to switch over to the GNS530 for the approach procedure. I switch from INS to RADIO, select VOR, and navigate by GPS along the approach procedure until time to intercept the ILS (or LOC or VOR depending on the procedure). Then I need to press CDI on the GNS530 to select VLOC. (What I and many others have been doing is to tune the ILS to all 3 radios: Nav 1, GNS530, and Nav 2.). Now the GNS530 in VLOC mode is "in tune" with the aircraft, and I can now select ILS on the AFCS. This is a lot of switch work, but if done in sequence, it will work (with patience).

Now the HSI is another matter altogether, and there is a thread around here for that. Long story short, the distance on the HSI, as I recall, only display from the INS. Look up that other thread to make sure.

The photos below are not from the TriStar model, but the GNS530 is the same WT model in many MSFS aircraft models, so it works the same as in other planes.

Make sense?

Edited 6 hours ago6 hr by Nikita2024