The wet compass will only give you an approximate heading as well.

This is the scenario I use against compass turns: You are flying at night,
in turbulence, in the clouds, picking up ice, and your vacuum instruments
fail. Your kids are crying, your wife is bombarding you with questions, and
the mag compass looks like a washing machine. Would you use a compass turn
or a timed turn? If your answer was a timed turn, then you are guilty of
suiting the procedure to the situation, which doesn't pay off too well in an
emergency.

(I tried to put that scenario into the Instrument Flying Handbook, but it
didn't get past the FAA editors.)

Bob Gardner

"Andrew Sarangan" wrote in message
om...
Bob
I guess I have a different opinion. I have no trouble using the
compass even in light turbulence. Moderate turbulence is a different
matter. Perhaps this is because the airplanes at my FBO have bad DGs
that need to be reset every 5 minutes, and we just got used to reading
the compass in bumpy air. Regarding timed turns, they will only get
you to the approximate heading. For example, even if you are only 5%
off from a standard rate turn (which is hard to tell on the TC), you
will be about 10 degrees off after a 180-turn. In order to fine tune
that heading, one needs to know about compass errors. I've seen
students zig zag their way along a north heading because they didn't
understand how to compensate for the banking errors.

I do agree that the correction card is often overlooked because the
card is out of date or the numbers are simply impossible to read.
However, most of the correction cards I've seen are rarely more than 2
degrees off, which is well within the tolerance for flying approaches.




"Bob Gardner" wrote in message
news:WR5%b.56390$Xp.268321@attbi_s54...
Unless you are flying in unnaturally calm conditions, precision with the
wet
compass is hard to come by. IMHO compass turns should be eliminated from
instrument training and timed turns emphasized.

In my experience, few pilots pay any attention to the compass correction
card, probably because the cards themselves are usually out of date.

Bob Gardner

"Ben Jackson" wrote in message
news:3wZ_b.54783$Xp.264494@attbi_s54...
When you're flying partial panel, to what precision do you read the
mag compass? To the nearest 5 degrees? Estimate to the nearest
degree? How long do you go between readings and rely only on timed
turns?

For that matter, do you ever try to apply values from the correction
card? In IMC or even VMC?

--
Ben Jackson

http://www.ben.com/