"Paul Folbrecht" wrote:
Anyway, on to my question. A couple times now, when I've been
navigating direct, either to a fix or airport identifiable by VORs or
one that isn't (such as an uncontrolled field with no navaid), I've
been asked to "verify direct XXX" when I'm off course by a quite small
amount - no more than 10 degrees.

They may not be asking because they think you're off course, they may
simply want to verify what clearance you're flying. I get this question
almost every time I fly IFR direct from Mobile to Dothan, AL. It's a
short trip, but it uses the airspaces of four TRACONS, so maybe that has
something to do with it. Thanks to the GPS's being coupled to the
autopilot, I'm never off course by more than 100 feet, but I still get
asked.

1) Should I be concerned at all by being asked such a question by ATC?

Nah.

And 2) Just _what_ is the IFR "heading tolerance", anyway?? Meaning,
what sort of heading deviance is large enough that you can be violated
for it?

Well, controllers can only infer your heading from the motion of your
radar target; their displays don't have a heading readout. They aren't
going to react until you've been off heading long enough to look like
you're going somewhere other than expected. You usually won't get
written up for a violation unless you create a hazard, such as a breach
of separation minimums.
--
Dan
C172RG at BFM