D-100 MAGCAL

[Dave_Dollarhide]

I was assisting a friend who just bought a D-100 calibrate his compass. On the first attempt, I forgot to enter the inclination first, but then, like my D10A, I entered the mag. inclination and then went to the MAGCAL page. Using a wet compass, I went throught the procedure and cardinal headings, but an error message came up saying there was a -20 mag adjustment error. I went to the MAGADJ page and zeroed it out. Again, we went through the procedure, but with the same results. I again checked the MAGADJ page and it had reset to -20 as before. ...same on a third try. Any suggestions?

 

[dynonsupport]

Two troubleshooting questions:

What was the value for the magnetic inclination that you entered? Related, what is the zip code at your flying location?

Is the compass oriented with the mounting tabs down and the 9 pin connector pointed forward as specified in the installation guide? No other orientation will yield a usable calibration.

 

[Dave Dollarhide(Guest)]

The Zip is 32043....think I entered 59.5, but will have to double check. It was the same as I used on my D-10A. Also, when I go to the airport next, I'll ask Tom Dorsey, who owns the D-100, about the installation details you mention. I'm running interference for him at this point. Thanks for the quick reply. Dave

 

[Dave_Dollarhide]

I checked Tom's installation and he had installed the remote compass upside down, under the top of the airplane's fiberglass nose section (engine is in the rear). He configured a new mount and re-installed the compass with the tabs down. He then attempted another MAGCAL, but with the same results. I'll go over and swing the compass with him again, but in case we have the same results, are there any other thoughts? I read a caution in another string on this subject about moving the airplane while data is gathered for each heading and I assume that means even a slight amount. Maybe a windy day can cause a problem?

 

[dynonsupport]

Dave,
A windy day won't be a problem. We're averaging readings over a few seconds, so as long as the average position is correct, you'll be okay.

Please double check your inclination setting, and we'll look into anything else that could be the issue tomorrow.

 

[dynonsupport]

Also, note that if the EFIS-D100 is in a panel that is tilted in pitch, the EDC-D10A also needs to be tilted by the same amount. If the mounting angles of the EFIS-D100 and EDC-D10A do not match, your calibration will suffer.

 

[dynonsupport]

Furthermore, the panel pitch adjustment also needs to be set correctly for the panel that it is mounted in.

 

[Etienne]

I have another question: As I fly a taildragger, the compass (and efis) sit at about 20 deg nose-high when on the ground... When doing the calibration, do I need to raise the tail so that the aeroplane is in a flying attitude?

 

[Dave_Dollarhide]

There is no need to level your taildragger to calibrate. I went through this one when I installed a D-10A in my RV-4 a few months back. My compass is dead on after using a compass rose at a local airport.

 

[Etienne]

Thanks, that's good news

Unfortunately I don't have access to a compass rose, so it'll be the old fashioned method of standing 20m behind the aircraft with a handheld sighting compass lined up on the tail and prop

 

[dynonsupport]

If you have a GPS, you can taxi for a while and get the heading from that. Just make sure you are using a magnetic heading readout and not absolute heading.