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Compass Requirement

kmbusse

Active Member
I'm wondering what options people have used to mount a compass to meet the requirements other than right on top of the glare shield. I really love the unobstructed view on the 14 and hate to mount it there.
Has anyone mounted one in the panel over on a side out of the way, or elsewhere?
Kerry
 
Mine is mounted in my panel and it is as accurate as in my Super Cub was with it mounted on top. Mind you a Super Cub has steel tubing ever where.
It wasn't bad. We had one installed in the panel of our RV-10 also and that one turned out very good.
 
Don't think a whiskey compass its still required...

It would seem to me that a whiskey compass is NOT required as long as you have a magnetic direction indicator. For example, my Garmin G3x has a very sensitive magnetometer to sense direction, i.e. magnetic direction indicator.

The interpretation in AC 23.1311-1c section 8.8 would seem to allow this...


"...The phrase "magnetic direction indictor" is interpreted as "magnetic direction-indicator", not "magnetic-direction indicator".

You need a device based on magnetism that indicates your direction. That could be a floating-card type compass, or a fluxgate compass, for example.

Some interpretation of this phrase is given in AC 23.1311-1C section 8.8:

Under VFR operation, part 91, ? 91.205, requires a magnetic direction indicator (that is normally intended to be a compass) for heading information.

[...]

Section 23.1303(c), Amendment 23-62, amended the requirement from ?A direction indicator (non-stabilized magnetic compass)? to ?A magnetic direction indicator.? As new technology becomes more affordable for part 23 airplanes, many electronic flight instrument systems will use magnetically stabilized direction indicators (or electric compass systems) to measure and indicate the airplane heading to provide better performance.

[...]

Part 23 does not prescribe specific accuracy requirements for magnetic gyroscopically stabilized heading systems. Specific accuracy requirements for avionics may be found in the related TSO and, as acceptable means of compliance to ? 23.1301, in ACs, notices, or policy statements/letters.
Further, installation of the magnetic direction indicator is regulated by ?23.1327:


Each magnetic direction indicator must be installed so that its accuracy is not excessively affected by the airplane?s vibration or magnetic fields..."


 
Hi Kerry. You must be progressing well on that build to have this question.

My compass is mounted on my panel, top center. There were no problems from the MD-RA with that placement. I honestly cannot recall ever referring to it in flight other than during calibration, but it's there. I'm with you on not giving away that unobstructed view - not a big deal for the sliders since they have that bar running down the middle, but that view is one of the biggest advantages of the tip up canopy.
 
Bob - Note the OP is in Canada, may have different rules.
I put one in the panel of my -10, off to the right. It needs the correction card. Best I could swing it was still off by 10 deg N and S.
I can?t imagine ever needing to use it, unless, as in ?The Day the Earth Stood Still?, all electricity has been ?neutralized? -:)
 
mounting options?

?.could this be one of those gadgets that is FIRMLY velcro'd to the panel in it's new vibration-free mount.... for inspection, and then ah, removed for, ummm, safety and visibility enhancement!
( and returned to it's actual owner in the hangar next door!)
 
I bought a cheap one for around 70 bucks on ACS and put it in a 2.25 inch hole to keep the FAA happy. Seems to work just fine.
 
I don?t think you need one either - if you have an electronic version with your EFIS - at least in the USA. If you still want or need to have one, I have one I just removed from the panel of my RV4 for an upgrade that I?ll sell you cheaply. It is 2 1/4? and mounts in the panel. There are a couple wires attached to the back that are not used, so it may be lit. I would have to check. Let me know if you want this one.
 
Thanks!

I did not note the Canada location but I thought it might be educational to post the FAA section as I had the same question...

I am not planning on a whiskey compass...unless the DAR requires it...
 
Did a walk through on a Gulfstream G 550. There is no wet compass. What they do have is a solid state separate compass that is independent of the rest of the glass displays.
 
The wording in the CARs:
Power-driven Aircraft — Day VFR
605.14 No person shall conduct a take-off in a power-driven aircraft for the purpose of day VFR flight unless it is equipped with
...
(d) a magnetic compass or a magnetic direction indicator that operates independently of the aircraft electrical generating system;
...

I have a Dynon D10A with internal backup battery. In the event of a failure of the generating system, it still operates, therefore it is independent of the aircraft electrical generating system. Ergo, I have no wet compass.
 
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What about a Skyview along with it's back up battery ?

Your should be OK. You meet CAR 605.14(d). MDRA inspector would not accept this on my -9 but after consulting with TC, he had no choice to accept it. MDRA cannot be more restrictive than the CARs.

Michel
 
There are a variety of compass apps available for download to your phone. They are quite accurate, would be useful in a pinch.
 
Further info on this... The MD-RA site now has a PDF outlining compass requirements, that doesn't outright say that you can't use an EFIS instead of a whiskey ball.

http://www.md-ra.com/docs/C70E.pdf
(this is on the "Articles of Interest" page, bottom of the first section)

Where the regulations still fall behind with the times is that even though you have an EFIS-based compass, that once calibrated doesn't have deviations, you still need a compass deviation card.

At least, once I calibrated my D10A, I could put my nose on any axis of the compass rose and the reading was +/- 1-2 degrees, which was certainly no less accurate than my placement on the compass rose.
 
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