Handling

[jack111]

My Kitfox Classic 4 is just about unmanageable during fast taxi trials. I feel it is a real accomplishment when I stay on the runway.
I have a belt reduction Great Plains VW engine rated at 100 h.p. for take-off turning a 72 inch Sterba wooden prop. It also has a Grove main gear.
I took instruction from "Stick and Rudder" and Paul's Kitfox handled like a dream
Any suggestions how to tame this beast will be appreciated. Jack

[CoClimber]

I am probably the last person that should be replying to this but I have just been studying tailwheels. If you have the Maule, try removing the cam. This will prevent the wheel from free swiveling. It has been known to release too soon and the airplane will be unmanageable if that happens. Good luck.

[DesertFox4]

Might be an alignment problem with the main gear. Grove sells shims to solve alignment issues. http://www.groveaircraft.com/accessories.html
A couple degrees out and the ride can be exciting. Did a quick search and found many threads on fixing this. Below is a link to a thread with a photo tutorial on checking alignment then fixing misalignments.

https://teamkitfox.com/Forums/threads/2802-Wheel-alignment-a-photo-tutorial/page2

[jonstark]

An aircraft as light as a Kitfox IV is going to be a handful trying to control during high speed ground runs. I avoided it and merely taxied (a lot) at normal speeds making S turns along the way and intermittent stops.
You might want to check your wheel alignment.
...and stay in the grass!

jon

[efwd]

All the info needed is right in the Grove website. Get there via the Link at the top of the forum. That's what I used for calculating the angle of shim I needed. I also purchased my shims from Kitfox themselves as they are bit less expensive than what Grove gets for theirs.

Hmm, did that kinda remind you of Desert Fox 4?

[HighWing]

From the very beginning, high speed taxiing has been discouraged precisely because of what you are experiencing. I did it once and this on my second build having 900 hours in type. I lost it, but recovered which gave me tons of confidence to make the first flight the next day - this after not flying a Kitfox for about three years.

[jack111]

I am probably the last person that should be replying to this but I have just been studying tailwheels. If you have the Maule, try removing the cam. This will prevent the wheel from free swiveling. It has been known to release too soon and the airplane will be unmanageable if that happens. Good luck.
Co Climber Thanks but I have already disabled the castering feature on the Maule tailwheel. I should have mentioned that in my initial post. Jack

[HighWing]

One more thought. The Maule tailwheel that came with the early Kitfoxes was regularly abandoned by the builders. The Issue then was mostly tailwheel shimmy. I went to the 6" double fork Home Builders from Spruce. I also have about a half link of slop in the chain/spring link which was the talk of the day when most of the guys were building IVs. I have been chastised by A&Ps (One a Stearman expert) for that, but it is what works for me.

[efwd]

Lowell, are you saying you are being told you have the too little slop or too much? I only had shimmy problems with my original tail wheel. This new AB3224A tail wheel is solid and stable. I seem to feel the rudder horn spring working much better on the right than when I push the left rudder. Turning Left, I need to often use breaking. Both my springs have some slack and seem to be even but they are not operating the wheel the same for sure.

[HighWing]

The Stearman A&P wanted it tight enough that there would be a bit of tension on the springs. He saw it the day I ferried a Stearman owner to pick up his airplane after an annual. It was free advice. I guess I mention it because I don't believe there is only one right way for every make and model.

[Slyfox]

this is my thoughts on high speed taxi, don't do it. I believe aopa or eaa came out with an article discouraging people from doing a high speed taxi. when I finished my rv7 I went and got some fuel, taxied to the runway, got on the runway, put full throttle and lifted off the runway when it was ready to fly. that was my high speed taxi :rolleyes:. the 4 can give you a little bit of yahooooo, if taxi is fast. best to land slow and just have fun. one more thought, check your tailwheel, if it unlocks easy it may be your problem. my old tailwheel if it got crud in it, it would not lock and it was a handful when it did it. could be your problem. raise the tail and support it on blocks or something, than go in and put full rudder each way and check each time the tail wheel to see if it unlocked on you, if so that's your problem, fix it.

[jack111]

this is my thoughts on high speed taxi, don't do it. I believe aopa or eaa came out with an article discouraging people from doing a high speed taxi. when I finished my rv7 I went and got some fuel, taxied to the runway, got on the runway, put full throttle and lifted off the runway when it was ready to fly. that was my high speed taxi :rolleyes:. the 4 can give you a little bit of yahooooo, if taxi is fast. best to land slow and just have fun. one more thought, check your tailwheel, if it unlocks easy it may be your problem. my old tailwheel if it got crud in it, it would not lock and it was a handful when it did it. could be your problem. raise the tail and support it on blocks or something, than go in and put full rudder each way and check each time the tail wheel to see if it unlocked on you, if so that's your problem, fix it.
Dear Sly,
I modified my Maule tailwheel so that it wouldn't unlock and caster. I had read a number times that the Maule had a problem with going into unwanted caster. At 77 yrs. old (me, not the plane), it makes it a bit difficult to maneuver into the hangar but it is doable. On second thought it has nothing to do with my age, it's just a bear to push backward. Jack

[Dusty]

From memory of an earlier plane I had with a maule, the trick was to use a flat screwdriver and unlock the tail wheel manually before backing into the hanger.A modified sack barrow is Also a handy tool.

[av8rps]

A Kitfox is not a difficult tailwheel aircraft to fly. I'm stating that for any of those out there reading this forum that have an interest in a Kitfox but have never actually flown one. I've been flying these airplanes since 1987. They are great handling aircraft both on the ground and in the air. But, like any airplane if something is wrong with it, normal good handling characteristics can be compromised.

Also, I personally do not think there is anything wrong with doing high speed taxi down a runway. If one is afraid to high speed taxi, what are you going to do the first time you feel the need to wheel land? Or maybe one day you just land a bit too hot and you find yourself (mistakenly) having to transition from a high speed taxi until you can get it slowed down. Or when you need to "Land long". Maybe it is just me, but I always high speed taxi an aircraft before I fly it for the first time (as in a 1st flight of a homebuilt) as I want to know what to expect BEFORE I find myself in the air. I need to know how to handle the aircraft in a high speed mode for the 1st landing IF I NEED TO DO SO ON THAT 1st FLIGHT. Again, maybe just me? I guess I'm pretty old fashioned as I still like to stall any airplane I fly on a regular basis...and I keep hearing that there are those that don't think we should be doing stalls? Oh well, to each their own.

I too would suspect that Maule tailwheel as they typically give the same symptoms. I had a Model 4 that had horrible ground handling problems. It had been ground looped and damaged 7 times before I got it. The Maule tailwheel was the biggest culprit, but one of the main landing gear legs was also tweaked out more than a half inch. So it was a monster. But easily tamed by straightening the alignment of the gear, and putting a different tailwheel on it.

[Slyfox]

wow! here you got a new airplane and you are saying it's ok to do a high speed taxi. What are you going to do when you want to do a wheel landing, well lets put it this way. just wait until you know your airplane, do 3 point landings. work your skills better, than do the wheel landings. that's what I suggest. JMHO. why chance cracking it up before you even take a first flight. trust me, I can do wheel landing better than most, I love them, but if your skills aren't there and the airplane isn't set up perfect, well your going to have a bad day and you will be rebuilding your airplane

[efwd]

I concur with AV8RPS. I heard stories of people having alignment issues on landing and as they put it "be prepared for a wild ride". I wasn't going to risk that so I aligned with shims and high speed taxied it. I told John and all that he said was "be careful, many of the high speed taxi tests turn into first flights". Well, I had made sure that I could handle the airplane before I did this and felt confident that even if that had happened I would have been prepared. Anyhow, I hated wheel landings while getting my tail wheel endorsement at S&R. I was sure I would not be doing them for some time. Then the tailwheel shimmy thing happened. I started doing wheel landings almost out of necessity and now I kind of enjoy them.

[Slyfox]

now you state that there was a tail wheel shimmy. when I do a wheel landing I let the tail come down on it's own, generally slow. so I don't have the tail wheel down at a high speed, generally pretty slow. so again if you do a high speed taxi, you should also be lifting the tail a little to get it off of the tail wheel. probably why john said you might end up lifting off. I didn't want to do any high speed taxi on my rv so I just took off. that took care of my high speed taxi test, lol.

years ago I watched a guy land a kitfox and had a high speed when he let the tail down, that tail wheel started spinning in circles, I couldn't believe it, he still was going straight forward, weird. don't know if he felt it or not, I didn't talk to him. I was on the runway getting ready to take off.

[Smiffy]

Hi Chaps

Could I ask your opinions on the following please.

Main legs.
I'm currently putting a mk2 back together and having stripped and rebuilt the under carriage legs, I've measured the tracking. I've got 0.5 deg toe-in on the port wheel, and 1.0 deg toe-out on the starboard wheel. Bearing in mind the mk2 has the earlier solid axles with no option to shim them, should I be concerned with this alignment?

Maule tailwheel
I've noted the comments earlier about removing the cam plate to prevent unlocking. Mine doesn't unlock on full rudder anyway, I'm just wondering how it affects taxiing when you need to turn tight on the brakes. Oh, it has all been stripped, cleaned and greased and unlocks fine on the bench, it just doesn't have enough lock on the aeroplane to unlock it.

Haven't taxied it yet, just finishing final assembly, but hopefully being inspected this month.

[jmodguy]

Smiffy
Your gear still needs aligned. Find a long bar that will fit the axle and someone/something to hold the tail and tweak the gear until alignment is proper.

[av8rps]

Again, maybe just the way I like to do tings, but I will always spend a bunch of time taxiing a new airplane so I know everything is working like it should before I leave the ground, and so I am comfortable and familiar with everything in the cockpit for when I do decide to fly. High speed taxi of a plane on wheels is the equivalent of step taxiing a plane on floats. There is no better way to know how a seaplane is going to fly, or to familiarize a plot to a new seaplane than to have him step taxi it. Yet I have many friends that have flown floats for decades and are still not comfortable step taxiing their own airplane. I don't get any of that. If we are going to fly our airplanes well, we need to train until we get good with them.


wow! here you got a new airplane and you are saying it's ok to do a high speed taxi. What are you going to do when you want to do a wheel landing, well lets put it this way. just wait until you know your airplane, do 3 point landings. work your skills better, than do the wheel landings. that's what I suggest. JMHO. why chance cracking it up before you even take a first flight. trust me, I can do wheel landing better than most, I love them, but if your skills aren't there and the airplane isn't set up perfect, well your going to have a bad day and you will be rebuilding your airplane

[avidflyer]

Smiffy
Your gear still needs aligned. Find a long bar that will fit the axle and someone/something to hold the tail and tweak the gear until alignment is proper.

I've used an 8' long pipe, put the nut onto the axel when you bend it so you don't bugger up the threads. To get more toe out is easier then toe in, cause you can tie onto the tail wheel area and use a cable come along to pull on the end of the pipe. It does take quite a bit of power to bend the gear. Most will say that 0 to 1/8" toe out is best. JImChuk

[CoClimber]

Back when I was doing wheel alignments to my race car, I hated measuring toe in inches. The problem is that I don't know the reference. Is it 1/8" difference from the outer edge of the tire? What if you have bush tires? I prefer degrees, but I happen to be really good at trig. I will be checking the alignment of my model II soon but, fortunately, it looks like zero degrees toe is a good number to shoot for. I am so grateful for this forum because I would be guessing about so many things otherwise.

Doug

[avidflyer]

I forgot to mention, when I check the toe in/toe out on the wheels, I jack the plane off the ground a bit, put a mark in the center (width wise) of the tire and with the mark all the way forward, take a measurement. Then spin the wheel 180 degrees so it's all the way back, and measure there. If you measure to the side of the tire, sometimes the tires aren't perfect and your results would not be accurate. Also, I pull a string from the tailwheel to the front of the plane in the center (sideways) of the plane and measure off that string. That will tell you if one wheel is more off kilter then the other. JImChuk

[JAMES20011]

I agree with slyfox, I tried high speed taxing, Was new to flying, never cracked up but came to close to often, Now I have 500+ hrs and high speed taxi quite often , Wheel landings do a great job of teaching taxing .

[Dave S]

Jim Chuk's method of measuring toe in/toe out is spot on. Before alleged "hi-tech" methods (subject to various degrees of correct calibration) were use in aligning car front ends, spinning the tires against a chalk stick and then a fine point to make an accurate line to measure from with a trammel bar from was the standard TI/TO method; and highly accurate. Also like Jim's method which permits accurate measurements of each side from the centerline of the aircraft.