DME Arcs

The GNS430 allows you to fly DME arcs by asking you to choose the IAF (specific radial). What happens if ATC vectors you to intercept the arc at another point - say the middle of the arc.

If you are being vectored to any segment of the arc that is loaded, fly manually or with HDG until you are ready to intercept the arc, then just press NAV twice. The GNS will setup an intercept to the closest point on the arc (this is just like with any other segment of the active flight plan).

Steve -
This one can be a little tricky. Just tried it on the Garmin 430 sim to be sure I had it right.

If being vectored to a DME Arc approach,

  1. Load and activate the approach, but hand fly or use AP to fly assigned heading. The approach segment which will be active will be current location to the arc endpoint.

  2. When assigned a heading to intercept the arc, flip to the Flight Plan page, press cursor, highlight the dme arc segment, press Direct to, confirm you want to activate the DME Arc segment.

  3. Now that the DME Arc segment is active, you can intercept the arc and go into NAV mode to track the arc.

How you handle the intercept depends on which AP you have. With the 55x, if you press HDG and NAV the AP will fly the assigned heading to intercept; if you just press NAV, the AP will intercept at a 45 degree angle. If you press NAV twice, the 55X will intercept on a 45 degree angle in GPSS mode. On 20/30, I BELIEVE you’ll need to hand fly to the arc, then hit NAV.

If you’ve got the time, try the sim - its great for trying out approaches you haven’t done before.


Roger - I tried it on the sim and it works fine -thanks for the help.

Steve Swartz