Magnetic Compass

[Bcone1381]

I wonder what Mag Flux number would if I placed it on the top of my instrument panel where the compass be installed? I wonder what I need to provide an accurate compass reading.

Zkelly, have you measured your Mag Flux number yet? My "Mag Flux" number when I put my phone on top of the instrument panel was 43. That is about what the number was when I was walking out to the workshop. I'm not worrying any more about this and will install the classic whiskey compass there.

Using the iPhone app to obtain a quantifiable number to the magnetic issue sure removes the hocus-pocus element for me. If I cant measure it or I choose not to then its luck if it works, and a mystery if it doesn't. A Mysterious problem can suck enthusiasm out of me for the project. A man has got to know his limitations.

[whee]

Maybe consider a Sirs compass. That’s what I would put in if I had needed to. The EFIS magnetometer meets the requirement so you’ll only need one it you want one.

I haven’t navigated off a compass or really even looked at one in forever. I actually don’t even know if my EFIS heading is accurate. Guess I should check that. Avare on my Samsung tablet works good though😉

[zkelley2]

Zkelly, have you measured your Mag Flux number yet? My "Mag Flux" number when I put my phone on top of the instrument panel was 43. That is about what the number was when I was walking out to the workshop. I'm not worrying any more about this and will install the classic whiskey compass there.

Using the iPhone app to obtain a quantifiable number to the magnetic issue sure removes the hocus-pocus element for me. If I cant measure it or I choose not to then its luck if it works, and a mystery if it doesn't. A Mysterious problem can suck enthusiasm out of me for the project. A man has got to know his limitations.

Nah, I decided it's more trouble than worth.

[svyolo]

I think the best location for a wet compass would be top of the windscreen, centered. Get it farther away from anything electric in the panel, and farther from the engine.

[zkelley2]

I think the best location for a wet compass would be top of the windscreen, centered. Get it farther away from anything electric in the panel, and farther from the engine.

It's not the panel that is the issue. The steel frame is ferrous and even somewhat magnetic in areas. Putting a compass near the v brace makes it point at one of the tubes.

From doing some reading on other forums on this, it appears you can degaus a metal frame but it will just remagnatize with flight after so many hours.

[svyolo]

It looks to me the top of the windshield has the least metal proximity, followed by the top of the instrument panel.It is close. Every tube and fabric airplane has one somewhere. It is obviously doable.

I know you are required to have some magnetic reference by regulation. I just can't imagine a scenario other than WW3, or a gigantic hack attack that leaves me with nothing more than a whiskey compass.

[JimParker256]

svyolo wrote "I just can't imagine a scenario other than WW3, or a gigantic hack attack that leaves me with nothing more than a whiskey compass."

And I doubt I would have a critical need to go flying in either of those scenarios... LOL

A lot of people swear by their SIRS compass. I've had incredibly good performance from Precision Vertical Card compasses in my last 3 airplanes (including the tube-and-fabric '65 Citabria I'm flying now). Most of the people who report problems with these devices are not using the correct mount for their airplane, or the "cushions" in the mount are totally worn out. (Although one airplane did require the optional "compass compensator" (ACS part number 10-07900), because there was so much residual magnetism in the frame.)

But I expect to just use the remote magnetometer with EFIS to meet the requirement.