Rudder installation question

[Greg Arehart]

I have been installing the empennage on my 9A and today test fit the bottom fiberglass tip of the rudder while the rudder is installed on the VS. To my surprise, it hangs down about an inch below the fuselage and binds when the rudder is swung either way. This cannot be right, as I have not seen hanging rudders in any photos, and it seems very unaerodynamic. The simple cure seems to be to trim the fiberglass tip (top part where it is riveted to the metal attachment strips on the rudder) by about an inch. That would allow the bottom forward portion of the fiberglass tip to be slightly above and in line with the fuselage and nest in the space behind the VS. However, I wanted to see whether there is something that I'm missing before cutting. (the top and sides of the rudder all look normal and line up perfectly with the VS).

thanks,
greg

 

[MTBehnke]

Hi Greg,

IIRC, I had to trim a bit off the top like you mentioned. There should be some barely visible lines in the tip showing roughly where the cuts need to be made, including around where the rudder horn angle sticks out. I extended a straight-edge along the bottom of the rear fuselage to align the bottom of the rudder fairing.

 

[AllanC]

Yes, I had exactly the same problem. i took lots of time to carefully trim the fairing, and was disappointed at the alignment with the fuse. Only then did I notice the very faint lines in the gelcoat.....trimmed to the lines and it fitted perfectly and in line with the fuselage. Took 3 days to get the fg dust out of my hair and clothes. My wife thinks she is allergic to the cat - I think its my fg dust which hangs around despite showers. Daren't tell her......

Allan

 

[scard]

Yeah, just start hacking on it until it fits.

 

[Greg Arehart]

Yep, went out this morning and indeed there is a faint line there that I had not seen before, so I will be cutting and sanding this evening. Thanks for your help.

greg

 

[MTBehnke]

I ended up cutting the rudder bottom about 3/16" above the line at the front to best align it with the fuselage bottom. I then tapered it to meet the line at the back. The cut-out for the rudder horns were close for the front and back of the angle, but didn't cut it as deep as the bottom line.

 

[N941WR]

Yep, went out this morning and indeed there is a faint line there that I had not seen before, so I will be cutting and sanding this evening. Thanks for your help.

greg

Greg,

You didn't say if you are building a -9A or a -9. For those of us building a -9, we have to trim it even more so the bottom clears the tail spring. On the positive side, we don't have to mess with the NW fairings.

Click on this picture to see what I'm talking about: