help - whiskey compass has gone wild

The wet compass in my Cessna 150 has suddenly decided to indicate way off.
I took it off the dash mount and it reads nearly correctly when moved about
12" away from the instrument panel, and even better when out in the open by
itself. I got another wet compass from a friend, and as I moved it near the
instrument panel got the same effects. It's at least 40 degrees off and in
some places like when held over the firewall its over 90 degress off.
Nothing else has been done to the plane recently. Is is possible that
something in the plane that has become magnetized and is affecting the
compass ? Is there anything that can be done ? I pulled the nav-com out of
the panel and it didn't seem to make any difference. All this is happening
when the master switch is on or off, doesn't make any difference.

Try this:
http://www.sacskyranch.com/degauss.htm

Jim wrote:
The wet compass in my Cessna 150 has suddenly decided to indicate way off.
I took it off the dash mount and it reads nearly correctly when moved about
12" away from the instrument panel, and even better when out in the open by
itself. I got another wet compass from a friend, and as I moved it near the
instrument panel got the same effects. It's at least 40 degrees off and in
some places like when held over the firewall its over 90 degress off.
Nothing else has been done to the plane recently. Is is possible that
something in the plane that has become magnetized and is affecting the
compass ? Is there anything that can be done ? I pulled the nav-com out of
the panel and it didn't seem to make any difference. All this is happening
when the master switch is on or off, doesn't make any difference.

I inherited/found/got a nice yellow, sturdy flashlight. Only problem was
the nice magnet in it somewhere that made random changes to the
aforementioned whiskey compass.

The nice yellow, sturdy flashlight is now on my work bench at home.

Thx, {|;-)

Victor J. (Jim) Osborne, Jr.



take off my shoes to reply

"Jim" wrote in message ...
The wet compass in my Cessna 150 has suddenly decided to indicate way off.
I took it off the dash mount and it reads nearly correctly when moved about
12" away from the instrument panel, and even better when out in the open by
itself. I got another wet compass from a friend, and as I moved it near the
instrument panel got the same effects. It's at least 40 degrees off and in
some places like when held over the firewall its over 90 degress off.
Nothing else has been done to the plane recently. Is is possible that
something in the plane that has become magnetized and is affecting the
compass ? Is there anything that can be done ? I pulled the nav-com out of
the panel and it didn't seem to make any difference. All this is happening
when the master switch is on or off, doesn't make any difference.

Sounds like you may need to have the aircraft demagnitized. A good
shop should be able to do this for you.

You have something in the aircraft that has become magnetized.
Look for magnetic flashlights or magnets added to oil filters or chip
detectors on the oil pan. Got any head sets next to the compass?
Have you changed the speaker for the radio?
If the plane got struck by lighting it most likely is magnetized
especially the crankshaft.

Use the compass to find the source of the field. Move the compass
around. Where you get the most deviation is the strongest field.
This is very near the source of the problem.

If you have a poor ground connection for the starter the current can
flow some where else and magnetize some steel object that the current
is flowing through.

John


On Fri, 09 Jul 2004 22:48:17 GMT, "Jim" wrote:

The wet compass in my Cessna 150 has suddenly decided to indicate way off.
I took it off the dash mount and it reads nearly correctly when moved about
12" away from the instrument panel, and even better when out in the open by
itself. I got another wet compass from a friend, and as I moved it near the
instrument panel got the same effects. It's at least 40 degrees off and in
some places like when held over the firewall its over 90 degress off.
Nothing else has been done to the plane recently. Is is possible that
something in the plane that has become magnetized and is affecting the
compass ? Is there anything that can be done ? I pulled the nav-com out of
the panel and it didn't seem to make any difference. All this is happening
when the master switch is on or off, doesn't make any difference.

The compass in our Archer suddenly began reading 30 degrees off. A lot of
investigation eventually revealed that a small magnet that someone had
riveted by means of a thin aluminum bracket to the center windshield bow in
front of the compass, presumably to get it to read correctly, had become
dislodged. Because of "springback" in the mounting plate, it was not
possible to reposition it without first drilling out the rivet, so it was
taped back in place. We will fix it properly when we get a chance, but for
now, the small piece of duct tape is working fine.

--
Bob (Chief Pilot, White Knuckle Airways)

I don't have to like Bush and Cheney (Or Kerry, for that matter) to love
America

"Jim" wrote in message
...
The wet compass in my Cessna 150 has suddenly decided to indicate way off.
I took it off the dash mount and it reads nearly correctly when moved
about
12" away from the instrument panel, and even better when out in the open
by
itself. I got another wet compass from a friend, and as I moved it near
the
instrument panel got the same effects. It's at least 40 degrees off and
in
some places like when held over the firewall its over 90 degress off.
Nothing else has been done to the plane recently. Is is possible that
something in the plane that has become magnetized and is affecting the
compass ? Is there anything that can be done ? I pulled the nav-com out
of
the panel and it didn't seem to make any difference. All this is
happening
when the master switch is on or off, doesn't make any difference.