Tail Cone alignment and rigging M20C, SB M20-313A

[yvesg]

Hi guys,

I noticed a few flights ago that I had a left wing heavy situation. I found several threads where the rigging procedure is well explained so today I went to the airport and elected to verify if the rudder had the 1 degree deviation to the right when the nose wheel is up and the rudder pedals clamped.

So I clamped, I raised the nose wheel by lowering the tail tie down hook and took a look. Results:

The nose wheel was straight OK.

The rudder was almost straith with the vertical fin but was about 1 or 2 degrees to the right in reference to the tail cone.

The issue I have was is: The tail cone is not aligned straight with the vertical fin. I have a 2 - 3 degrees bend or something on the pilot side. (This would explain the left heavy wing). I went to look at another Mooney on the field and it seemed to have a similar misalignment but about only half of what I have.

My question is:

Is the tail cone supposed to be exactly aligned with the vertical fin?

The airplane had SB M20-313A done in the spring during annual and is it possible the mechanic who did this messed this up? This seem to be about when I started to notice the heavy wing situtation. Upon doing this SB, wouldn't we want to check if this affects the rigging?

Yves

C-FQKM

[1964-M20E]

• SB M20-313A is simply an inspection no real work unless the spacer plate was installed wrong. If all you saw was the SB complied with at annual then the spacer plate was in the correct position.
  
• I read somewhere I think on this board that the Mooney factory had an issue with the jig that was used on the tail cones of certain models and that there is a noticeable twist in the tail cone of the aircraft. This twist is supposedly quite noticeable when you look down a line of similar Mooney’s. As I understand it the factory engineers reviewed the issue and some of the airframes were reworked but most were within acceptable limits.
  

[yvesg]

I just searched the forum for tail cone and did not find anything. Some bolts were replaced when performing M20-313A. So then is the 1 degree to the right supposed to be relative to the fin or the tailcone?

Is that 1 degree to the right there to counterbalance the tail cone issue?

Regards,

Yves

C-FQKM