Compass

[DonMuncy]

My compass began leaking. Looking at prices, it seems that replacment is more feasible than repair. The manual shows my compass to be an Airpath C2450. Aircraft Spruce shows they have a C2400, but not a 2450. Anyone know whether this is a direct replacement, or will I need to call them.

Aircraft Spruce's price for theirs is $199.75. They show a Vertical Card compass for $270.

Has anyone priced compasses from Mooney sources.

I consider a compass in a K model, with a Garmin 430, to be a legal necessity, but superfluous.

My first impulse is to buy the cheapest one possible, but is the anticipated life enough of a factor that the change to a vertical card is a better deal.

I also did a little reading and found a guy on an EAA forum that repaired an Airpath , by using a repair kit. However, he replaced a diaphram in it. Mine is the bullet-shaped unit without a removable rear section which would house a diaphram. Has anyone ever had one of these apart. If a compass needs a diaphram, how does mine work without one, or is there one hidden back there where you can't get to it.

Anyone know anything about these.

[OR75]

i would respectfully disagree. Looks like a legal necessity but when everything else can fail, the magnetic compass won't.

if the earth magnetic lines fail .... we will have others things to worry about...

[carusoam]

DP

[DonMuncy]

Byron,

The system says you can not receive any more PMs. If you will give me your e-mail I will contact you direct.

Incidentally, the Mooneyspace system seems to save all your PMs unless you intentionally go in and delete them. I had the same problem and I deleted all my old ones.

[Piloto]

Consider a vertical compass http://www.aircraftspruce.com/catalog/inpages/vertcard_compass3.php

I had mine for five years and never had any problems or issues. Unlike the wet compass the card compass is very stable during turbulence making it easier to maintain a heading in turbulence. They never leak or tumble.

José

[Marauder]

Just a comment on the vertical card compass. I had tons of issues keeping the wet compass swung in my Mooney. I upgraded to a vertical card compass 18 years ago and haven't regretted it. The vertical card compass still needs to be swung periodically, but using the "balancing balls" feature, it is usually very easy.

It is my understanding that most of the time the reason our compasses get out of calibration is due to the effects of the steel cage being influenced by electrical current running near it. Not sure if this is true, but I made sure that any wire running current to the plane accessories is kept well away from the steel frame.

[jetdriven]

Byron,

The system says you can not receive any more PMs. If you will give me your e-mail I will contact you direct.

Incidentally, the Mooneyspace system seems to save all your PMs unless you intentionally go in and delete them. I had the same problem and I deleted all my old ones.

BDR737@gmail.com

[Marauder]

And for those who thought I have lost my marbles with my "balancing balls" comment, here is a link to the ones for the Precision compass: http://www.chiefaircraft.com/aircraft/flight-instruments/magnetic-compasses/pcn-pbb475.html

[1964-M20E]

If you decid to replace the gaskets get teh glas as well sometimes they like the compass and do not want to come off.

[Z W]

+1 vote for a vertical card upgrade. After you've used one it's hard to go back. If you're ever using it for real (electrical failure, possibly in IMC), you will be under stress and remembering that your compass is "backwards" and trying to read it bouncing around is one more thing for your brain to do.

[Oscar Avalle]

I also would vote for the vertical compass. Reliable and easy to intrepret.

[DonMuncy]

With a rebuild kit from Aircraft Spruce, their "filling aid" (which is quite helpful), a little help from the hangar elves, and a big boost from Byron/Jetdriven, (Thanks Byron), my compass seems to be back in business. Turns out the diaphragm had a hole in it.

Thanks for all the responses.

[RJBrown]

You guys are Great!!!

I picked up my J from Western Skyways last Saturday. It was there for an annual and a engine overhaul. They had it from 7/28/12 until 12/1/12, a little longer than the 12 week "estimate" they gave me. On the flight back from Montrose the compass was peeing on my foot. Low and behold just the moment I needed it there was a thread about just my problem. Well you talked me into it. With a trip to California on this Saturday now was the time.

Two nuts hold it to the airplane once loose the light gets unplugged.

Picture 1 shows the before with a "waterline" half way down the middle.

Pic 2 is the screw on the back ask about above.

Pic 3 cover is off. At this point all the screws come out. Both the diaphragm on the back and the glass on the front need "cut" off with a razor blade. The rear was taken off first and the remainder of the fluid drained. With both ends open you can clean off the old gasket material. The glass on the front goes on one way. Note the direction and side the bevel is on. The front gaskets are not symmetrical there is a top and a bottom. Once aware that there is a difference it is easy to see the difference in how they fit.

Pic 4 is all the new parts in the kit.

The rear cover, 4 screws and the diaphragm are assembled off the compass. The compass is then filled with fluid and the back/diaphragm assembly is put on loosely. Recessed side towards the inside of the compass.

Pic 5 is the compass assembled in a new 2 cup measuring cup full of compass fluid. move it around and shake out the bubbles. This time it took 2 tries to get all the air out. Tightening the rear cover while submerged.

Pic 6 is the old parts note the notch the screwdriver is pointed at. Once all the air is out and all the screws are tight you must cut this notch in the edge of the diaphragm so the wire to the light can hide while the cover is put on. Note how the straight sides of the front gaskets are different lengths. Black gasket goes beneath the glass and the cork one goes on top.

Pic 6 is ready to mount back in the plane. No waterline inside.

Total time 3 minutes each to mount and dismount in the plane. Plus about 45 minutes to repair the unit.

[carusoam]

Nicely documented RJ...

-a-

[jetdriven]

That sounds familiar. I "had a friend who did that" and it worked out great. Submerging it in fluid gets all the bubbles out.

[Chimpanzee]

Hmm,

I wanted to replace my old airpath with a vertical. My mechanic gave up after a few hours, because he couldn't get is swung and corrected, and stuck the airpath back in. As I am mostly away from my plane, I did not have the tiem to try myself, but I will give it a second attempt next time I am back in PHX, as I find the vertical compass much easier to read.

norbert

[Marauder]

Hmm,

I wanted to replace my old airpath with a vertical. My mechanic gave up after a few hours, because he couldn't get is swung and corrected, and stuck the airpath back in. As I am mostly away from my plane, I did not have the tiem to try myself, but I will give it a second attempt next time I am back in PHX, as I find the vertical compass much easier to read.

norbert

If you are having troubles swinging the compass, you may need the balancing balls I mentioned above. The steel frame in our Mooneys interfere with magnetic fields. I found that once I installed the balancing balls, I was able to get the compass to calibrate. Just don't permanently glue the balls in place (this is starting to sound like some sort of porno script). If your steel frame is being magnetized by wiring run too close to it, you will need to have your balls free (now it really sounds like a porno script) to recalibrate it. I use a little dab of hot glue to keep it in place.