DOES YOUR SCOTT 3200 "STEER" W RUDDER PEDALS

[MoonlightVFR]

I am curious as to how many members have Scott 3200 tailwheel that works correctly over an extended period of time.

It has been over 20 years since i have seen one disassembled and as I look at the Parts diagram in exploded view I can no longer recollect the exact role that each part performs.

New parts were installed in my tailwheel and it was a great feeling to really "steer" but alas after several months it no longer worked.

I use the differential brake gently and aerilons to "Sail" in ground manuvering.

It is time for me to be re- educated

regards

[GAHorn]

The friction plates act similar to a clutch and pass along steering inputs to the fork/axle/wheel. Until they are overserviced with grease. Then they slide around and refuse to work properly.

Most folks live with that and use braking, just as you described.

[bsdunek]

As George says, they get over greased and then they don't work right. Everyone wants to pump the grease in until it comes out all over.
I tell my AI "DON'T grease the tailwheel - I'll take care of it", and then I don't have any trouble.
There is a sort of 'C' shaped spring that catches in notches on the steering arm plate. There is then a cam that unlatches the spring from the notches when the wheel is pushed to the side enough - the unlocking feature. The friction plates dampen the steering mechanism to reduce the chance of shimmy.
I find that cleaning everything up and then just a light coating of grease on any contacting surfaces works well. Don't tighten the king pin nut more than necessary. I also keep the tire pressure at or near the maximum recommended - seems to work best that way. Good steering, no shimmy (assuming the king pin is vertical) - no problems.

[rbarry]

George
What period of time would you recommend on service, cleaning and how much disassembly is required. Is this a "if it ain't broke don't fix it" or preventable maintainance item. Mine was rebuilt about 500 hrs ago and seems to work OK.
Russ

[Robert Eilers]

rbarry,

There is a good article in the AVWEB Columns titled, The Dark Side Of Maintenance. The column suggests that maintenance when not necessary can create problems.
See: http://www.avweb.com/news/savvyaviator/ ... 909-1.html

Column number #53 - Savvy Aviator.

I had problems with tailwheel shimmy after I purchased my C170 - everything I tried to correct it failed. Finally, I gave up and purchased a new Bushwheel Tailwheel (Basically a Scott). I haven't had any problems sense. I was most surprised by the definit "clunk" the new tailwheel makes when going to full swivel. The old tailwheel made no noise at all.

[N2865C]

The friction plates act similar to a clutch and pass along steering inputs to the fork/axle/wheel. Until they are overserviced with grease. Then they slide around and refuse to work properly.

Most folks live with that and use braking, just as you described.

I put on a new Scott around 300 hours ago. I have never have greased it (except wheel bearings) so I know it hasn't been over serviced. I still need to use brakes for taxiing.

[cessna170bdriver]

Cleo Bickford, charter member of TIC170A, and owner of the same 1953 B-model since 1959 says of the less than stellar tailwheel steering on 170's: "That's just the way it is." My experience agrees with his.

MIles

[blueldr]

That's why Cessna changed the steering cabling on the '55 and on models on the C-170s and C-180s.
However, from my viewpoint, there was not much improvement in my '55 C-170. It still needed mostly differential braking.

[cessna170bdriver]

That's why Cessna changed the steering cabling on the '55 and on models on the C-170s and C-180s.
However, from my viewpoint, there was not much improvement in my '55 C-170. It still needed mostly differential braking.

That's also been my experience in my '55 model, regardless of the amount of grease, or whether the tailwheel was 35 years old or brand new; brakes are required for steering at normal taxi speeds. Not a big deal.

A little off-topic, but the '55 and later steering system is infinitely easier on the rudder horn, as the tailwheel is steered from cables from the fuselage rather than from chains from the rudder horn.

Miles

[hilltop170]

Mel Wick at Wick Air in Palmer, Alaska, 907-745-4322, has a multiple 337 field approval for the tailwheel steering extension mod shown below. It is very effective in improving the tailwheel steering angle and responsiveness.

With the multiple 337 field approval, Mel can approve the 337 himself in block 7. without any requirement for block 3. sign-off by the feds.

You would have to check with Mel but I can't see why the mod could not be installed and signed off in block 6. by your local IA in any state.

[Bruce Fenstermacher]

One of the reasons that mod is effective is the increase throw of the longer control arm. Of course the better chain angle won't hurt either.

I would think that since the multiple 337 is for Mel and Mel only that only he and no one else could do the approvals. Kind of like owning an STC that you don't sell but can use on what ever aircraft you the owner would like.

The difference being you could sell the rights to use an STC to someone else but you can't sell the right to use the 337.

[blueldr]

From the picture shown, I would think that the part attached to the rudder horn would put a rather severe twisting moment on the rudder horn. After all is said and done, the effective pressure vector is from the rudder cable attach point to the connection on the tail wheel assembly.
The longer downward the attached arm extends, the straighter the pull on the tail wheel horn , but, the more severe the twisting moment on the rudder horn.
Over all, the vector remains the same.

[hilltop170]

Bruce-
I haven't asked him, but I would think Mel would be happy to sell the parts, installation instructions, and 337 referencing his multiple approval with block 7. signed.

Unless Mel's multiple approval specifies somewhere he is the only one allowed to do the installation, which I don't see anywhere on his approved specifications, any IA should be able to install it and sign block 6.


BL-
The extension arm is 1" wide by 1/8" thick 4130 and bolts to the rudder horn in three places and also attaches to the rudder hinge by using a longer bolt thru the hinge. The hinge bolt provides reaction to the bending moment imposed by the downward bent arms, not just the rudder horn itself. In the past, I have had the arms of the rudder horn crack just from the spring tension on the factory installation. It looks to me like the arm strengthens the rudder horn assembly due to its additional attachment to the hinge.


In any case, it greatly improves the tailwheel steering and I don't need to use as much braking as before to taxi.

[GAHorn]

Richard, ... Mel is in Alaska, where field approval rules are much more relaxed ... and whose field approvals are NOT transferrable to the lower 48. Alaska citizens are "more equal" than lower 48 citizens.

(Mel's mulitple approval is most probably for Mel's multiple airplanes.... not for reassignment to another owner's airplanes.)

[hilltop170]

George-
You may be entirely correct and it cannot be installed anywhere else except Alaska, but geeze, FAA approval should be FAA approval. The F stands for federal (although I can think of a few more descriptive meanings) and should apply anywhere the FAA has jurisdiction! I have had other 337 field approvals approved in Alaska and installed in the lower 48. The planes were registered in Alaska but installations were not done in Alaska. No one has said they are not legal.

So, are you saying if someone from down south flies up to Alaska, he can't have the mod done while he's there? Or are you saying that only Mel can install his multiple 337 in Alaska no matter where the plane is registered? If it can only be installed in Alaska, are you saying it's not legal outside of Alaska? I don't think so. What if Mel comes to Texas on vacation, isn't his IA and repair station license good anywhere in the USA? If registered location of the plane is the governing factor, that's really screwed up. I'm confused!

I guess I should have asked Mel before I opened this can of worms.