National Aeronca Association Bulletin Board

I think I may need to replace my sagging tailwheel spring.

My question is. If the spring(s) are sagging and making getting the kingpin vertical or negative resulting in slight shimey on pavement.

Do I need to replace all the springs or can I just replace the longest spring that attaches to the tailwheel?

The reason I ask is htat Univair prices the whole set at $123 but you can buy each individual spring at a cost of between $25 and $40.

I assume the $40 spring would be the long one and if this would solve the problem, I'd rather spend $40 instead of $125.

Thanks,

TomD

I don't think the old leaves would match the curve of the new one.

I replaced TW springs on both my Stinson and now the Champ, it is an inexpensive solution to a bunch of problems.

I doubt that any original spring has anywhere near its original arch and is the cause of a bunch of TW problems.

$123 is one of the cheapest part prices you will ever pay that will do so much good!!

Thanks,

I'm also thinking of buying and installing the aviation products tailwheel. This is the same one they use on the "new" Champ that is currently produced by ACA.

It will save a couple pounds at the very far end of the moment arm and also get rid of my Maule shimmey. I've been told that saving that weight way back there wil lmake the airplane fly =better and more reactive due to less inertia. Also going from the 8" maule to the 6" tailwheel also slightly changes the AOA in the three point attitude.

The aviation products tailwheel is "only" $255 complete (well I may need to buy new tension springs to connect it to the rudder arm). I could probably sell my Maule on e-bay or someplace for nearly that amount.

I don't know what the Maule is selling for these days but I've had very good luck with them. I found that the main shaft bushing is the most common cause of problems and replace mine every few years. They cost very little and save the shaft and casting from wearing.

I've never had any problems with Maules and I fly out of my farm pasture.

The regular service Maule I have on my Champ now is the old one from my Stinson which I replaced with the Maul heavy duty model many, many years ago because the Stinson tail is very heavy.

It also works much better now with the compression steering springs in place of the tension ones, I should have changed years ago.

Airplanes actually fly more efficiently and a bit faster when a bit tail heavy. The reason is that the horizontal tail actually pushes down in flight which loads the wing more. If this load is decreased by a more aft CG the wing doesn't have to support that extra load. Since most of us fly with the rear seat empty this rear bias is even more important. I usually carry a heavy toolbox in the rear to help this problem.

Check your elevator trim sometime after flying solo with nothing in the rear. Don't add nose up trim for landing, leave it in the cruise position and you will be surprised at the amount of nose up trim required for level cruise. So, a little extra weight at the tail is not a bad thing unless you mostly fly with a rear loading.

My maule tailwheel was rebuilt with new bushings in it before I purchased it and only like a 120 hours flight time. WHich probably not many miles on the ground.

I think my first and least expensive way to proceed is to replace the entiere tailwheel leaf spring set. This may align the kingpin better and my shimmy problem will go away.

I understand what you say about tail weight. But with limited useful load, saving a couple pounds goes directly to useful load. My CG is pretty far forward with a metal prop etc. This is another reason I'd like to switch from my old Bendix mags to slick mags. Not only easier starting but also save I think at least 5 pound if not more.

It is easy enough to counteract the fwd CG by loading useful stuff into the baggage comp since it is so far aft.

It is pretty hard to load a Champ with too much stuff. I usually strap my bag into the rear seat and my toolbox into the baggage comp.

I haven't yet removed the rear stick but am about to do that next time I go XC. I sure don't want a bag shifting and fouling the stick!!

I know nothing about the aviation products tailwheel but am interested in hearing from you about it if you get one.