Stan Prevost writes:

The point, though, was to have the magenta line along the final approach
course, not on the direct path between the present position and the fix.

On the GNS530, you can insert a waypoint into your currently active
flight plan. If you put it after the current fix, it will be inserted
in your current route from your last waypoint. I don't have it in
front of me so I don't recall the exact sequence, but you can put
stuff in and take it out on the fly.

Approaches are different, though, since changing them seems to mutate
them into regular routes. I don't use approaches and the like too
much on the GPS, since it's harder to get it working than to fly it by
hand (or by autopilot).

--
Transpose mxsmanic and gmail to reach me by e-mail.