Most important M20J structural component

[CCAS]

Not really, but....

After four years of owning my 1989 M20J I've had to repair/replace my cracked plastic compass case a couple times due to excessive vibration of the center post where it was mounted. No matter what I tried, the compass seemed to shake (often times violently) during most phases of flight. I read about other Mooney owners with a similar problem so I just chalked it up to how Mooneys behave.  

Then during my recent Annual Inspection, the shop identified a discrepancy (among others) for: another cracked compass housing and a missing compass 'clamp'.  I asked, "What the heck is a compass clamp"?  See the circled part in the photo.     

Let's just say that with the clamp installed, the compass doesn't shake and it now actually reads within a degree or two of my HSI heading. I feel a bit foolish for not knowing earlier but I'm happy with the discovery.  Best of all, it wasn't a very expensive fix.  

[Falcon Man]

Good post. None of my Mooneys had a compass clamp - where did you find that?

[CCAS]

Surprisingly, the Mooney factory had them in stock.  Your local MSC should be able to order one.  

[LANCECASPER]

9 hours ago, CCAS said:

Not really, but....

After four years of owning my 1989 M20J I've had to repair/replace my cracked plastic compass case a couple times due to excessive vibration of the center post where it was mounted. No matter what I tried, the compass seemed to shake (often times violently) during most phases of flight. I read about other Mooney owners with a similar problem so I just chalked it up to how Mooneys behave.  

Then during my recent Annual Inspection, the shop identified a discrepancy (among others) for: another cracked compass housing and a missing compass 'clamp'.  I asked, "What the heck is a compass clamp"?  See the circled part in the photo.     

Let's just say that with the clamp installed, the compass doesn't shake and it now actually reads within a degree or two of my HSI heading. I feel a bit foolish for not knowing earlier but I'm happy with the discovery.  Best of all, it wasn't a very expensive fix.  

You would think they could have come up with a shorter brass screw for the top hole and put the head on the front.

[Pinecone]

31 minutes ago, LANCECASPER said:

You would think they could have come up with a shorter brass screw for the top hole and put the head on the front.

Since I grab the center post when getting in and out, I would prefer the heads towards the windshield.

But agree that they should have used a shorter screw, or cut that one down

[N201MKTurbo]

Wow, I haven’t seen a mic in a Mooney in a long time.

[EricJ]

I got tired of constantly repairing those plastic mounts, mostly from getting bumped by passengers, maintainers, me, etc.    I put in a full-face dry compass that has a floppy mount and have had zero issues since.

 

[BlueSky247]

2 hours ago, LANCECASPER said:

You would think they could have come up with a shorter brass screw for the top hole and put the head on the front.

Any longer and they could use that for a cupholder bracket.

[LANCECASPER]

Since I grab the center post when getting in and out, I would prefer the heads towards the windshield.
But agree that they should have used a shorter screw, or cut that one down

Any screws that I've seen like that have an acorn nut on the front

[A64Pilot]

4 hours ago, N201MKTurbo said:

Wow, I haven’t seen a mic in a Mooney in a long time.

I keep mine in the pocket in the front of the seat, with the spare headset batteries

I’ve had a mic on my headset go bad once, then I called tower on the phone and they gave me light signals, since then I keep a mic in the airplane. 

[Pinecone]

I have the mic in my plane.  Right now it is a convenient place to coil and hold the excess hose going to the O2D2 unit.
 

[CCAS]

3 hours ago, BlueSky247 said:

Any longer and they could use that for a cupholder bracket.

I plan to hang my fuzzy dice from it

[N201MKTurbo]

44 minutes ago, A64Pilot said:

I keep mine in the pocket in the front of the seat, with the spare headset batteries

I’ve had a mic on my headset go bad once, then I called tower on the phone and they gave me light signals, since then I keep a mic in the airplane. 

There are always a couple of headsets on the back seat. My old M20F always had a hand mike in the seat back. When I first bought that plane, I used the speaker and hand mic.