Thorp Air Command - T18.net

I have come to the conclussion that the aluminum block on my Trusty-Style ACS taiwheel assembly has become worn and, as a result, allows the tailwheel to break out with minimum pressure. Two wind related unlocks on our recent trip to Texas bring me to this conclussion. Anyone out there had similar experiences and what did you do to fix it?

My ACS tailwheel has been in service for ten years and about 1000 hours.

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Bob Highley
N711SH
SN 835
KLAL

FWIW, I too have seen a ACS (Aviation Products) tailwheel mech worn out. I don't know the hours on it. The bore becomes egg shaped at the top and bottom and the shaft wobbles in the bore. I suppose you could bush it, but that would weaken the housing. Probably best to buy a new one. Keep'em lubricated..... Also, I can tell that the exhaust flow hits my tailwheel in flight, probably this will contribute to additional lubrication needs.

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Dave M
Sacramento
ex-T-18 owner

I think I saw a parts list somewhere on this site or the last one. They may sell you the block by itself.

Mine is starting see some wobble between the steering arm and the top of the block. I'm going to shim it.

d

Bob,
A new "attach block" is probably available from the manufacturer, Aviation Products Inc., in Ojai, CA.
They are listed in the latest catalog I have from them, for $76. Telephone 805-646-6042.

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John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

I posted an updated AP parts/price list about 2 months ago. It listed individual parts you can buy from Aviation Products. 10 YEARS in service ! The arm/"pin" would seem to get the most wear ? Keep that Baby "lubed up !"

RB

While the ACS tailwheel is a good fit for the Thorp, the aluminum casting leaves something desired. I too have the ACS wheel and over the years it has become loose. Looking at the casting there is no easy fix. I would like to see the results from the "Flyboy's" tailwheel attachment, anyone using it? The RV guys praise the tailwheel.

bill flyboys lives a mile from me what would you like to find out? I can bring some samples to kentucky dam .

Bob,
I just recently replaced the control arm on my Aviation Products tail wheel. I had excessive play between the arm and the shaft, measured 0.021". I also found that the slot in the control arm that engages the locking pin had become worn. This allowed a shimmy on landing hard enough for the tail wheel to break free. I only did that twice, the first one was a real attention getter when it happened. Replacing the control arm fixed my problem.

I called Aviation Products direct, explained the situation and they sent me a control arm and locking pin and said to let them know if that fixed the problem and then they would figure out if I owed them any money. Good people to work with.
I paid them for the control arm and they said to keep the locking pin just in case.

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Bruce Finney
N18JF T-18C #262
Yelm, WA USA

I agree with Bruce. Worn control arm, where the pin sits and a worn pin. I had some play and replaced the arm and the pin and that greatly reduced the play.

RB

Thanks to all for your input. First of all, I found that the tailwheel was made by Aviation Products, Inc. of Ojai, CA. and not ACS. I replaced the block and it fixed the problem I was having. A word of caution: The new block was 1/4" shorter than the one I replaced. Luckily, I had enough adjustment left in my rudder-to-tailwheel arm cable to take up the difference. The advise to not trust the grease fitting for proper lubrication was spot on. One other thing I did was to invert the pin from the original position putting the unworn area up. My arm showed no wear. I would replace the pin and spring as well next time.

I did look for alternative tailwheels and investigated the Screaming Eagle assembly from Flyboys and found it to be a good unit, however it only comes in a 15 degree angle and we need ten. I plan to look at them, again, at OSH.

I was pleased with the service and help at API and Karen got the unit to me in FL in just two days via USPS.

_________________
Bob Highley
N711SH
SN 835
KLAL