Jim Macklin wrote:
If you're down to just the compass, worry more about keeping
the wings "level" and less about heading. The compass, in
the northern hemisphere will work as the sole instrument
only when flying south [saw between 150-210] heading. It
will be very sensitive and indicate the correct turn
direction.

I'm not sure I follow. During my CFII training I got a solid 2 hours of
flying partial panel with compass turns. I was able to fly exact
vectors to ILS, etc. If I was off even by 2 degrees when I rolled out
on a heading my CFII would yell at me. I can tell you from experience
you 100% can fly very, very exact headings in any direction using
compass turns if you know how to read the compass and account for the
effects. I'm not saying doing so in IMC would be as easy as it is under
the hood but personally, I would do that in a second before trying to
do the math required of timed turns while under the pressure of partial
panel IMC. Of course most of us have GPSs which are actually a much
better partial panel way to figuring heading (approximated as course).

-Robert, CFII