"Roger" wrote in message
...
On Sat, 25 Nov 2006 16:14:36 -0700, "Matt Barrow"
wrote:


"Mike Noel" wrote in message
m...
ps Check out:

http://www.firstmarkaerospace.com/standbycompass.asp


Also, this thing is much less prone to errors:
http://www.aircraftspruce.com/catalo...rd_compass.php
and http://www.pai700.com/index.html

I've had a vertical card compass for years. The Deb had one in it when
I go it so I'd hardly call it a new, let alone "totally new" concept.
Like a whisky compass it does not give the proper heading at all
times. You still have the lead and lag in turns and it won't set
still in turbulence, but it has far less movement than the whisky
compass in turbulence.

I'd say about one-fourth the movement in any case. What surprised me was how
much less overshoot/undershoot there was during turns. I suspect it's from
being mounted in a jeweled gimbal (?) which dampens movement, instead of
floating in water

The only times (I think) that a whiskey compass is any good is on the ground
or in dead still air during 1.0G accell/decell.

How pilots used to navigate with them alone (wait for some cementhead to say
"they used watches and maps, too") is a testament to their skills.