A 100 KIAS with a 50 knot 90 degree crosswind can be flown
without any compass at all, you just need a stable heading
reference, but it is so far from being close to any easy
reference, it tells you nothing about the compass accuracy.

You need an accurate compass/heading reference for ADF
tracking and it does help with getting and staying on course
with radio navigation.

The question is not how bad can it be, but how good can it
be.



--
James H. Macklin
ATP,CFI,A&P

"Casey Wilson" N2310D @ gmail.com wrote in message
news:Y3Flg.22377$YI2.20622@trnddc01...
| I've got no problem with that George, as a general
indication of
| discrepancy. On the other hand, I sure that some of the
nitpickers in our
| RAP community would want to immediately toss in the VOR
calibration and
| accuracy, crab angle caused by crosswind drift relative to
the actual course
| versus heading, yadda, yadda...
|
| What my question really is, is how much difference (for
discussion I'll
| agree that the method described is acceptable) between
that compass heading
| and the VOR radial is tolerable before the airplane should
be grounded and
| the compass readjusted, repaired, or replaced? Secondly,
what is the
| applicable reference for that?
|
|
| "GeorgeC" wrote in message
| ...
| I had a thought, what do you think? If you are tracking
a radial on a VOR
| couldn't you compare the radial to the compass heading
and get a good idea
| of
| the compass error?
|
|
| On Mon, 19 Jun 2006 14:17:23 GMT, "Casey Wilson" N2310D
@ gmail.com
| wrote:
|
| Thanks, I know about compass roses and swinging the
compass. What I'm
| looking for is an indication that the compass needs
swinging. That's why
| my
| hypothetical scenario stated that the runway alignment
is correct. That
| does
| happen, by the way, even if the odds are against it.
|
| GeorgeC
|
|