Magnetic Compass

[zkelley2]

Has anyone found a good place to mount an old fashioned non remote mount(EFIS) compass?

I have two sitting around and they both have errors of no less than 30 degrees and up to 90 depending on the direction when anywhere near the panel. And there's nothing in my panel at the moment.

[alaskabearhawk]

Take a degausser to the fuselage tubes and then see what you get for readings,

[zkelley2]

Take a degausser to the fuselage tubes and then see what you get for readings,

Seems a lot easier said than done.

anyone tried this? https://m.aircraftspruce.com/catalog...passshield.php

[alaskabearhawk]

I have a hand-held degausser used for erasing tape recordings. It looks like a small iron for clothing. Seems easy enough to me.

[Bcone1381]

I've had some magnetism issues on my fuselage and would like more information on hand held degausser as well. Uncertainty of my issues will remain until I get the fuselage outside where I can swing it around.

But I can help one way. My iPhone has a $3 app called Smart Tools Pro with a bunch of hand gadgets. One of them is a tool called Mag Flux that measures magnetic field strength. I can easily find points of magnetism on the fuselage with it. Right now it reads about 43. But when I get up and move it next to the telephone ear piece it jumps up to over 1000. In fact I can see that the magnetic sensor is near the iPhone camera lens by way move the phone around on the telephones handset ear piece.

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.

Alaska, can you help out the OP a little more? Did you use it to degauss your fuselage, how successful was it, how long did it take? Will you share the Brand name, methods of using it, name of degausser, age, cost? Will you rent it out?

[alaskabearhawk]

It's nothing fancy. Just pull the trigger and move it around on the steel parts. The cockpit area may take 30 minutes...

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[zkelley2]

It's nothing fancy. Just pull the trigger and move it around on the steel parts. The cockpit area may take 30 minutes...

20190629_112213.jpg20190629_112303.jpg20190629_112144.jpg

It'd be cool to try that. You mind if I borrow it for a day or so?

[alaskabearhawk]

You would be better off just getting one off ebay. Postage alone would be around $32 round-trip. Plus I'm not too keen on loaning out tools. Best intentions and all, compost does happen and it usually happens at inopportune times.

[svyolo]

Seems like a lot of work for a wet compass. Pull out your smartphone, go to google maps, drop a pin where you want to go. Or get a free GPS app which gives you your course and speed.

With one EFIS, one tablet, and 1 smartphone, I have as many navigation backups as an airliner. If I have a passenger with another smartphone, I have more.

The GPS app works perfectly at FL350 and .8M. It is a brave new world of cheap, consumer navigation.

[Chris In Milwaukee]

Fair enough, except we’re still required to have one (a magnetic direction indicator).

[jaredyates]

My magnetic direction indicator uses a sensor in the wingtip.

[Chris In Milwaukee]

Yep, a good option if you’re using glass.

[Bcone1381]

Seems like a lot of work for a wet compass. Pull out your smartphone, go to google maps, drop a pin where you want to go. Or get a free GPS app which gives you your course and speed.

With one EFIS, one tablet, and 1 smartphone, I have as many navigation backups as an airliner. If I have a passenger with another smartphone, I have more.

The GPS app works perfectly at FL350 and .8M. It is a brave new world of cheap, consumer navigation.

The debate for the need of a wet compass is a really good subject on it own. If we can keep this thread focused on improving the accuracy of a traditional magnetic compass it will help those of us who plan to install and use one.

I'd like to ditch the magnetometer. These guys

https://aerovonics.com/av-30

make a DG that is independent of a magnetometer, but requires the pilot to manually realign it occasionally. In the previous century I did not find doing so to be an inconvenience at all. Today as I plan my build, this system seems like the simplest to install and potentially trouble shoot of any I've run across.

Lastly, As think about my mag compass placement, top of the instrument panel I think will place it furthest from any steel tubing in the fuselage as its away from the diagonals that run down from the wing root to the firewall, the window side posts, and the bottom cross tube that the panel sits on top of.

Brooks

[rodsmith]

Fair enough, except we’re still required to have one (a magnetic direction indicator).

I'm unclear on this, I'm thinking an EFIS that uses a magnetometer fills the requirement. If that is true, then a wet compass is optional as a backup.

[tailwind]

Mine is licensed without a fluid compass. I have a dynon with internal backup and a Garmin efis with electrical backup. Also I carry a iPhone with Garmin pilot. Three effective methods of navigation in the event of electrical failure.

[Bdflies]

Having read, what I thought was the applicable regs, I was left a bit unclear about the requirement for a wet compass. I asked my DAR if I was required to install such, considering that 3 GPS receivers reside in my panel. He laughed and pulled his phone out. "This thing will get me anywhere I need to go!" was his reply. The G5 battery is supposed to last 4 hours. Don't get me wrong, though. I have no aversion to a nice old fashioned compass and I do use one very regularly. I just didn't feel the need to have one, in the Patrol and haven't felt lacking.

Bill

[Chris In Milwaukee]

I'm unclear on this, I'm thinking an EFIS that uses a magnetometer fills the requirement. If that is true, then a wet compass is optional as a backup.

You’re right. OP didn’t mention an EFIS or similar; said there was an empty panel. Just have to have a magnetic heading source.

[zkelley2]

I have an EFIS that's going in, I was just thinking for a backup for IFR. Seems imprudent to have a compass that is tied to the EFIS as a sole compass for IFR flight.

I mean we have 6 screens on the Boeing, but we have a fluid compass.

Might be overkill though. Reading 91.205 again, it looks like the EFIS remote magnetometer meets the reg for VFR day/night and IFR.

[jaredyates]

What does the correction card look like on the Boeing? On the Embraer card it's up to 30 degrees on some headings. Between the airframe errors, the dip errors, the lag, the traditional compass is not something that seems useful to me. But in preparing for instrument flight, your comfort is what matters, not anyone else's of course.

[zkelley2]

Honestly I dont even know.

What I'm trying to do is have backups for ifr.

In instrument training compass turns worked great.

[svyolo]

I don't remember being taught the use, correction, or anything else in any commercial aircraft. Maybe in 95-96 when I was an FE on a 727 I had to know something.

I guess if you have an old school DG that you need to reslave, a wet compass has a use. Other than that, knowing your course is much more useful. If you know your course, even if it comes off a phone, you have better navigation than a wet compass.

A couple of years ago they installed some com equipment on our 737's that were causing dual FMC (old school IFR navigator) failures. All of our flights were overwater/class II (no radio navaids available)/ETOPS. But we had a wet compass. But we also had 2 IPADS. We never even glanced at the compass. It was a bit annoying, but kind of a no brainer. Heading select and keep yourself on the magenta line on the IPAD.