Here's a reference to a 19-page paper by Jim Terpstra of Jeppesen.
On page 6, there's a description of "Fly-Over" vs. Fly-By" fixes.
http://www.bluecoat.org/reports/Nav2001Bluecoat.pdf

Basically, he says that 'Fixes are charted as fly-over fixes only when
specified by the governing authority.'
I think that says there's no fixed rule, and you dare not guess.
If Jeppesen places a circle around the fix, you must fly over it.
---JRC---

"Greg Esres" wrote in message =
...
Can anyone suggest any reasons why you shouldn't use GPS or DME to
lead your turns when approaching a fix, such as an IAF, on a non-GPS
approach? (Meaning that you don't wait for complete reversal of the
nav instrument.)
=20
The AIM has a couple of requirements for a "complete reversal" of the
TO/FROM indicator, but they aren't instructions about how to fly an
instrument approach. Regardless, those injunctions may be outdated in
a GPS world.
=20