Wheel pants causing left turn, what is best way to fix?

lancef53 · #1 05-05-2010, 08:45 AM

I just started flying my 8 in April, and flew for the first 15-20 hours without the wheel pants. After I installed them, I noticed the plane wants to pull to the left. What is the best way to correct it, and how do I figure out which one I installed crooked? I don't have the intersection fairings on yet, just the gear leg fairings and wheel fairings.

Just to clarify, all the measuring should be done with the plane hanging level, and the gear relaxed, correct? It is easy to find the center of the back of the fairing, but not so easy to find the center of the front.

Do I fix this before the intersection fairings are fitted, or do those first?

The plane seemed to fly straight before the wheelpants, so I think it is the wheelpants causing the problem.

Thanks, Lance

f1rocket · #2 05-05-2010, 08:56 AM

Is your ball centered? That should be your judge as to whether you are flying straight or not.

Surprisingly, the wheel pants tend to have a minimal impact on the flying characteristics unless they are way off. Control surfaces have a much more significant impact and I would suggest checking there first. For example, my Rocket shed the bolt that holds the pant on to the axle once and I could tell something was different, but even with the pant bending way down, it didn't have a significant change to the flying characteristics.

If you want to check your alignment of the pants, jack up the airplane and take the weight off the gear and use a laser level to check this. It may be that now that the air is flowing smoothly around your tires, that a more noticable out of rig condition in now more apparent?

BTW, if you change the wheel pant alignment, do this BEFORE installing the fairings. Ask me how I know.

rich · #3 05-05-2010, 09:37 AM

Lance,
I had the same problem. MY left gearleg fairing needed a little tweeking.
Take the gear leg fairings off and fly with just the wheel pants and see if it still pulls left. If it does you will need to look at the wheel pants.
Good luck,
Rich

JoeBlank · #4 05-05-2010, 09:56 AM

Lance,

Yes, the wheel/gearleg fairings should be installed/aligned with the gear unloaded (aircraft jacked off the ground).

The gear leg fairings are more likely to have a turning effect. They are essentially mini-airfoils. I found that they had a quite dramatic effect on stability when I first installed them. As Rich noted, eliminate the gear leg fairings to further identify which component is affecting the flight characteristics.

Intersection fairings won't have much affect on stability but will increase speed a little. Obviously you will want to work through this procedure prior to installing the fairings:

http://www.vansaircraft.com/pdf/Wing_Heavy.pdf

Bavafa · #5 05-05-2010, 10:14 AM

Getting the wheel pants and gear leg fairing lined up right will have a long lasting affect on your flying and speed, so I would take as much time to make sure those are lined up right. Also, not sure how you are keeping the gear leg fairing in place without the intersection fairing.
As to your specific question about finding the gear leg fairing center, just wrap a string around the intersection fairing (around the middle part) and pull it back to the back tail side of the plane, equal distance from the center of the fuse both in the front and back side. Then adjust the gear leg fairing in such way that the trailing edge of the fairing is in the middle of the two strings.
If this does not makes sense, give me a call and I be happy to explain it verbally as it may be easier that way. You can reach me at 530-417-5713

Good luck

lancef53 · #6 05-05-2010, 02:23 PM

OK, I will check those things.

With the 8 flat gear legs, do you need to shim the leg to turn the fairing?
It doesn't seem like the fairings on the 8 would have as much room for error as the planes with the round gear leg models, but maybe I am wrong?

Thanks, Lance

ao.frog · #7 05-05-2010, 03:04 PM

My -7 flew straight as an arrow both with and without the wheelpants.
when I installed the legfarings however, the ball was about one half width out of center.

Both fairings was 100% aligned with the a/c centerline when I checked after landing.

I then moved the left fairing clockwise so it's trailing edge moved about 1 cm outboard. (1 cm isn't much!) and then the ball was in the center again.

lancef53 · #8 05-08-2010, 01:39 PM

The weather finally let up today, and I got to fly a little bit. The ball is to the right a small amount, so that the ball is up against the right line, but not out of the line. This is with the wheelpants on and the manual aileron trim about 2/3's of the way to the right. If I put a little pressure on the right rudder, the ball centers.

I will try without the pants and see what happens.