Kitfox 4 left turning tendencies.

[THRC12]

I have a 92 model Kitfox 4 that I'm currently flying every day possible. It has 80 horse 912 and 3 blade Warp, taper tip. No bad habits at all except for the dreaded left turning tendencies. No issues out of the ordinary anywhere but cruise. 80-85 mph and if you let go of the pedals it will seriously yaw to the left. Wind direction will obviously make it better or worse. I do have a bendable trim tab and it's bent pretty good. Worst yawing is with a quartering tailwind from the left. I have played with it in different wind directions and for the most part it's always there. Should I maybe do a bigger tab, or maybe consider a tick of right thrust in the engine? Tab is about 3x5 and bent probably 35-45 degrees now. Headwind from the right and it's pretty good. Thanks!

[jiott]

That much yaw sounds pretty excessive to me. Have you checked the vertical fin for being out of alignment or bent? If everything else is OK, possibly a bigger bendable trim tab will help; I have a 2x6 tab on my SS7 bent about 30 degrees and it flies straight with feet off pedals.

[THRC12]

It's actually only excessive in the left quartering tailwind. Definitely, absolutely nothing bent. All other conditions it's mainly just a moderate nuisance having to keep a bit on the right rudder. No wind at all and it is just a faint turn. Only in cruise I think I mentioned. Power on stall and it's only a tick of right rudder when slow and pitched up. Never drops a wing in any stall conditions power on or power off.

[aviator79]

The wind direction should not have any affect on this. Steady winds only affect how your airplane moves relative to the ground. Have you checked flaperon rigging?

The few Kitfoxes I have flown are not as statically stable in yaw as a garden-variety Cessna. They require that the pilot use the pedals to keep it coordinated. I understand early models had pretty much neutral yaw stability. This has been improved, but the airplane still has short coupling to the vertical stab and rudder.

[PapuaPilot]

The wind direction should not have any affect on this. Steady winds only affect how your airplane moves relative to the ground.

Have you checked flaperon rigging?

I totally agree with the first statement. Wind doesn't have any affect on this.

Also, you might want to check that the wing's angle of incidence and washout are the same on both sides (as well as flaperon rigging). One thing you can do to check this is fly the plane, center the ball with the wings level. The plane should not turn if it isn't disturbed by gusts or bumps. If it turns then you probably have a wing or flaperon rigging problem.

One more thing, make sure your ball is centered when the plane is level. Otherwise you are chasing the wrong problem. Check this first.

[THRC12]

Not saying it will not fly hands off. Wing rigging and flaoerons are perfectly the same both sides. If wind direction doesn't have any effect on your course, then why course correction? Just asking, because it is Only prominent in specific wind directions. I'm talking in the 10-30 kt range. It's earlier model 4 with smaller rudder. Straight headwind and and it's hands off to very slight. I can put a bigger trim tab no problem, I'm just thinking that by holding right rudder or having a tab do it for me, I'm inducing drag unnecessarily. Thanks!

[Wheels]

I have the same plane with a 912UL. I drift a little left as well and just deal with it. that said, I put a couple degrees of angle on the engine mount with spacers when I first got it. No effect at all. Wast of time and effort. Do the trim tab, check for alignment, eat your veggies.
Jay

[THRC12]

Kinda what I'm thinking. Thanks. I'm going to maybe make a trim tab I can clamp to different places on the back of the rudder to find the sweet spot. I don't want to be drilling holes up and down the rudder for nothing. As far as making changes and finding out whether it likes it or not, I can fly it with or without the trim tab, flip it around, whatever doesn't matter, just would like have it a little better. Lol By that I mean it isn't a problem if I have to hang my leg out the door, I can fly it.

[Wheels]

Awhile back I asked about the trim tab and one of the guys on the forum had used double sided sticky tape and a piece of aluminum to attach a trim tab. He said it was still on the plane after 2 years. I need to resurrect that thread and do the trim tab install as well. I"m tired of the drift like you. My right foot gets tired.
Lets collaborate and find out where the best placement is for the trim tab. I"ll start playing with it in the next couple of days. I just need to be home so I can fly.

[jiott]

It could have been me that said I used a piece of aluminum and double sided automotive trim tape. It is now 5 years and 700 hours and that trim tab is still there with no sign of coming loose.