AirPath compass documentation

[Ibra]

Hello,

Does anyone has the overhaul manual for this beast?

https://www.aircraftspruce.com/catalog/inpages/airpath_compass4.php

AIRPATH C2400 L4VT OVERHEAD COMPASS LIT 12V NORTH

 

Out of curiosity why Southern Hemisphere would result in an expensive compass? I know that our fellow Mooniacs in SA or OZ are used to fly upside down and have their Christmas in the summer, however, I don’t think that justify +11$ 

 

 

Edited September 13, 2023 by Ibra

[N201MKTurbo]

The magnetic lines dip towards the poles. In the northern Hemisphere a small weight is added near the S end of the compass card to compensate for this. In the southern hemisphere the weight needs to be at the N end. 

[Fly Boomer]

1 hour ago, Ibra said:

Hello,

Does anyone has the overhaul manual for this beast?

https://www.aircraftspruce.com/catalog/inpages/airpath_compass4.php

AIRPATH C2400 L4VT OVERHEAD COMPASS LIT 12V NORTH

 

Out of curiosity why Southern Hemisphere would result in an expensive compass? I know that our fellow Mooniacs in SA or OZ are used to fly upside down and have their Christmas in the summer, however, I don’t think that justify +11$ 

 

 

Looks like instructions come with the overhaul kit from Spruce.  Also, this video, while slow, seems pretty methodical.

https://youtu.be/KoPGyNOFPCk

[Shadrach]

1 hour ago, Ibra said:

Hello,

Does anyone has the overhaul manual for this beast?

https://www.aircraftspruce.com/catalog/inpages/airpath_compass4.php

AIRPATH C2400 L4VT OVERHEAD COMPASS LIT 12V NORTH

 

Out of curiosity why Southern Hemisphere would result in an expensive compass? I know that our fellow Mooniacs in SA or OZ are used to fly upside down and have their Christmas in the summer, however, I don’t think that justify +11$ 

 

 

Have you considered a SIRS?  I think its a better compass and worth the extra $70. Mounting may be a challenge. 

 

[EricJ]

2 hours ago, Ibra said:

Hello,

Does anyone has the overhaul manual for this beast?

https://www.aircraftspruce.com/catalog/inpages/airpath_compass4.php

AIRPATH C2400 L4VT OVERHEAD COMPASS LIT 12V NORTH

 

Out of curiosity why Southern Hemisphere would result in an expensive compass? I know that our fellow Mooniacs in SA or OZ are used to fly upside down and have their Christmas in the summer, however, I don’t think that justify +11$ 

In the US not even an A&P/IA can work on or "overhaul" a compass.   They're supposed to go to an instrument shop/repair station.    So, not as many people have a lot of experience with them, also because they don't really need work very often.

That said, places like Aircraft Spruce sell repair kits for them, because there are an awful lot of hangar fairies that fix them when needed, and they need parts.

https://www.aircraftspruce.com/catalog/inpages/repairkit.php?clickkey=15492

Edit:  ^^That page shows an overhaul manual as the last item, so they apparently do exist in the wild.

They're really simple, and filling it without leaving any air bubbles in it seems to be the most challenging part.   Some peopl...uh, hangar fairies, suggest submerging the entire unit in fluid and do the final reassembly submerged.   

Any southern hemisphere units built in the northern hemisphere, apart from being a different part number, need to be tested separately.    I think all of that just adds a little cost to the southern hemisphere units.    When the magnetic poles flip we'll have to see how it affects compass costs. 

[N201MKTurbo]

5 minutes ago, EricJ said:

When the magnetic poles flip we'll have to see how it affects compass costs. 

I'm not sure that will be on the top of my list....

[Ibra]

1 hour ago, EricJ said:

That said, places like Aircraft Spruce sell repair kits for them, because there are an awful lot of hangar fairies that fix them when needed, and they need parts.

I am not sure if we have many of these around here? hangar smurfs maybe? 

1 hour ago, EricJ said:

Edit:  ^^That page shows an overhaul manual as the last item, so they apparently do exist in the wild.

Thanks, I missed that one