Tailwheel a *****cat on grass but a wild animal on pavement

[jiott]

Here's a easy way to check main gear alignment; Make sure the main tires are inflated the same and then attach a 8 or 10 ft piece of pipe.....

I would strongly suggest you don't lay the pipe across the face of the tires. Use spacer blocks and lay it against the wheel face. Iv'e seen tires with very uneven sidewalls; it could give a very false reading. You are really trying to evaluate the rolling axis of the axles.

[avidflyer]

If you jack up both tires at the same time, put some masking tape on the center of the tires, spin them with a pen held solidly on something so it doesn't move around against the tire, you will get a fine line that is exactly consistant on the tire. (not affected by sidewall bulges and such) Do that on both tires and then you con measure between the lines on both tires. To see which gear leg is more out of whack, you can tie a string on the tailwheel spring, and pull it forward down the center of the plane at the same hight as the axles. With the string tied off ahead of the tires, Measure to the string and you will see how front and back of each wheel compares. Hope I explained it well enough so it makes sense. I'm about to do it again on the Kitfox 1, I'll have to take pictures. Jim Chuk

[avidflyer]

I rigged up the thing I was talking about on the Kitfox 1 today, and snapped some pics while I was doing it. Found out that the left wheel has about
3/8" toein and the right side has none. I ended up drawing a pencil line on that cross 2x8, and put a nail on the line front and back of the tires. Making a mark on the tape and measuring it off the front nail, then rotating the tire so you can measure to that same mark off the rear nail should be very accurate. At least that's my story, and so far I'm sticking to it, although it is slightly modified from my earlier post. ;-) Jim Chuk

[jiott]

I don't want to complicate things too much here, but there are some differing opinions on setting the toe-in with weight on the wheels or not. I did mine like avidflyer with weight on the wheels (suspension) so it tracks straight after landing and weight is mostly on the wheels. I have had no ground handling problems whatsoever for 3 years now. However, there is a school of thought that it should be done with no weight on the suspension, simulating the first instant of touchdown. To me that makes little sense because nearly all ground handling/looping problems occur later on in the rollout. FYI, the toe-in/out measurements WILL be different with or without weight on the suspension.

[jiott]

By the way, you can jack up one tire at a time to get the marks on them by spinning, then set them back down on the ground to do the toe-in/out measurements. I snapped a chalkline in the floor for the plane centerline. Many ways to get the same job done.

[t j]

nicely said. I will restate this, land as slow as you can...

Here's my Kitfox hard to land story. Mine was a monster. I ground looped it severely and damaged the plane. I spent $5,000 plus a year working on and off to fix it better thnan new. Then I was afraid to fly it.

I went a got 15 hours dual from an old instructor with an old 1940 J3 Cub. He made me fly from the back seat only. Then I went to San Jose and got 7 more hours dual from an aerobatic instructor at Amelia Reed in a Model 4 kitfox.

Then I felt good about flying my kitfox. It was still a hand full but I felt confident until I landed kind of fast at an unfamiliar airport and got on the brakes a little to make the turn off and ground looped again. This time a slow one but scary as I found myself just along for the ride.

Then I checked the main wheel alignment and found the left wheel toed in about 1/2 -3-4 of an inch. I bent the axel cold in a vice with a sledge hammer to where both whels are now straight ahead.

It lands beautifully now. It's the easiest tail dragger I have flown to date.

Here's a video of what Sly is talking about. Slow the plane down and stay off the brakes. I have a Maul tail wheel set up properly. That is, it does not unlock at full ruder deflection unless I stab that brake and there is a little slack in the chains.

My landing check list FFFF...Fuel, Flaps (none for three point, about an inch or two for wheel landing) Fifty mph on final, Feet off the brakes. I'm usually about 40 mph over the numbers.

[Jerrytex]

So I checked my Maule Tailwheel and made a video. First off, sorry about the plane running up in the background. I didn't even hear it but the camera sure picked it up. The second thing is....I didn't have anyone operating the rudder pedals but I double checked and when I push the rudder pedals, the rudder goes to the stops in back so by pushing the rudder, I am essentially doing the same thing as pushing the pedals.

https://www.youtube.com/watch?v=e09o...ature=youtu.be


I guess maybe I haven't had any issues since I really can't remember ever maxing out the rudder. And also when I slip, I slip to the left so on that side, it appears the lock is working. I went ahead and removed the swivel plate. Its a pain to push the plane backwards now but it will be fine until I can get a different tailwheel.

[t j]

Slipping left you're pushing right rudder aren't you?

[avidflyer]

I was moving my Kitfox 4 project around today, and noticed that when I pulled the rudder up against the stop, for a right turn, the 8" maule tailwheel unlocked with no side pressure. For a left hand turn, it took quite a bit of pressure before the tail wheel broke free. I'll have to fix that before it flys. Jim Chuk

[av8rps]

I sure am glad to see that people are investigating their taulwheels and wheel aljgnments.

These planes if set up properly should be easy to handle tailwheel aircraft. So if your Kitfox is difficult, there's something wrong with it. And as we've learned on this thread, it is most likely either a tailwheel not working properly, or a gear/wheel alignment issue.

And if yours is so bad you are thinking it may require an exorcism, you probably have both a tailwheel and a gear issue.