Leg Fairing Alignment

I put my main wheel pants and leg fairings on before the last flight. Nose gear leg fairing has been on for some time (no impact on yaw). Before I did that, the ball was about an 1/8 out to the right. After the fairings, the ball was about a 1/4 or so out to the right. Interestingly, the plane listed to the right several degrees and would level out after stepping on the rudder and centering the ball, so likely it is adding some additional yaw. I can't imagine the extra 12-15 knots of speed could account for the additional yaw, though I really have no idea.

Curious for some opinions on possible remediation. Part of me thinks to just leave it and address with a rudder trim. The other part of me says maybe I pick up a knot or two by addressing it. The real question is how to address it. Do I just randomely move the leg fairings to the right to see what works? One, both, how much? It is easy to drill new holes for the lower intersection fairings, but not for the uppers. Also don't want to make it worse.

I used several strings and was pretty tight when installed, so I can't be off by much here from a tolerance stand point. Hence my concern. If it is off, I am sure it is s 1/16th or less. I also read an old post from Bob Turner, saying that he played with them quite a bit and could never address it with fairing movements.

Appreciate any input from those that have experience in this area.

Larry

I was very careful following Vans instructions when installing the fairings on my RV-10 and had no issues with yaw. The magic of fiberglass fairings is that you can easily plug the original screw holes and re-drill a new hole. Don?t settle for anything less than perfect here.

Yep - on the RV-10 you can move the ball from slightly out left to slightly out right by how you rig the gear leg fairings - and I proved this.

Recommend your get a second set of eyeballs to make sure they are really rigged right. If you are still out one way or the other, rig them slightly out to compensate - but both the same way and same amount.

If you get to the point where the ball is exactly in the same spot with the fairings off or on (and you can?t get it centered), then a simple tail trim tab, like this:


Carl

Thanks for the input. Turns out that the intersection fairings were the issue. I just threw them on without complete attention to alignment, figuring I would clean them up when permanently mounted. both of the long tails on the lowers were well bent in the opposite direction of my issue. Once straightening them out, I am back to where I was without pant/fairings.

I'll get everything cleaned up and add a rudder trim as necessary.

Larry

Carl Froehlich said:

........then a simple tail trim tab, like this:

Carl

Click to expand...

I'm having trouble figuring out what you've done. Could you post a side and/or bottom view?

He made a "Gurney flap" or "wickerbill", on the base of the tail lamp.

See wiki.

alcladrv said:

I'm having trouble figuring out what you've done. Could you post a side and/or bottom view?

Click to expand...

Just a simple piece of 0.032 aluminum, cut to fit the tail light mount but with a tab sticking out on the needed side. A hole is cut on the middle to allow the tail light and of course the tail light mounting screws. The tab is thus sandwiched between the tail light and the rudder.

I stole this idea from someone else on VAF. It will put a ball that is touching the line or slightly over back in the center.

I would not make the tab much bigger than this. If you need a bigger tab then suggest the traditional wedge approach.

Carl

Ok, thanks. I had just wondered if it was faired into the lower rudder fairing on the forward side.