heavy wing after installing wheel fairings

billnaz · #1 04-22-2007, 10:29 AM

I just put on my main wheel fairings and now have a heavy right wing. Not bad, but noticable. First flights were w/o fairings and I had no control issues. I've heard of yaw induced by fairings but never roll. I thought I'd lined "em up pretty well per the instructions. Anyone had a similar experience? Any solutions short of moving them? Or how much might I need to move them to effect roll? My 6A has the old gelcoat white fairings.

hevansrv7a · #2 04-22-2007, 02:25 PM

I have only flown mine for two takeoffs since installing the fairings, but I think I have the same issue. Mine is a -7A and the wheel fairings are SJ's but the leg fairings are standard. I think I have the same effect and had none before. It's in the paint shop now, so well see what's up when I get it back. The rolling tendency is much more noticeable on takeoff than in cruise.

robertahegy · #3 04-22-2007, 02:36 PM

The takeoff roll may be a flap not the same as the other. Do you have the same effect whether you use flaps or not?

Roberta

Norman CYYJ · #4 04-22-2007, 02:38 PM

Take the wheel pants off and test fly the plane. If it still has the problem you will know the fault is with the gear leg fairings, if all is well then the only thing left will be the proper alignment of the wheel pants. When you put on the wheel pants just fly it with the main gear pants if okay the fault is in the nose wheel pant. Easiest way I know of finding the problem.

hevansrv7a · #5 04-22-2007, 02:50 PM

Quote:

Originally Posted by robertahegy

The takeoff roll may be a flap not the same as the other. Do you have the same effect whether you use flaps or not?

Roberta

Thanks, Roberta, good idea, but I don't use flaps on TO so no factor in my case.

billnaz · #6 04-22-2007, 08:02 PM

In my case the role dendancy is more pronounced at speed. I don't take off with flaps either. The plane flew fine prior, and adding main wheel pants was the only mod I made, so it looks like they are the culprits. I'll take em off and see for sure. I was wondering what I was gona do to keep busy while I fly off my 40 hrs! There's always somthin'!

JordanGrant · #7 04-24-2007, 05:36 AM

I had/have the same problem on my -6. I flew the airplane for over a year without the fairings, partly because of yaw and roll problems when I finally got around to fitting them up. I did a lot of experimenting with them to try and figure out the best place to set them up. I did several flights where I intentionally "mis-aligned" the leg fairings a little to see if I could straighten out the airplane. I basically was trying to make the fairings into a trim tab of sorts. I could trim out the roll, or the yaw, but not both due to the inherent aerodynamics. I even tried flying with the leg fairings on only loosely, so the fairings would streamline with the relative wind. That sort of worked, but it didn't lead to a perfectly straight-flying airplane. The end result was that I found a position that was decent compromise at cruise speeds, so I went with that.
So for a data point, I had the same kind of problem. Aerodynamics are funny like that. Even stuff like the propellers slip-stream impacting the wheel pants and fairing can have an effect, so even perfectly aligned fairings can induce some yaw by their very presence.
Good luck!