Tailwheel control horn problem

[krines]

Got a 51 A model. Broke off the tab that connects to the control horn (by 2 rivets) where the tailwheel steering springs eventually attach. Ordered new tab for 260 bucks from Cessna and it looked to be the right shape but was slightly off in size and did not fit. Had this happen 6 years ago on the other side. The replacement tab then was 80 bucks and fit perfectly. Any suggestions? Sorry I do not have a PN or picture at this time. Steve

[bagarre]

Is this the aluminum tab up on the rudder horn?
http://www.redskyventures.org/doc/cessn ... Manual.pdf

Page 28 Figure 15 Part 14 - PN 0433132 Tab Tailwheel Steering?

Could you simply make one up out of the right thickness aluminum using the old one as a template?

[Metal Master]

Per the Cessna 170 Type certificate the Scott tail wheel is supposed to be installed per the Scott Bulletin I-168. If you have a copy of the Scott Bulletin I-168 you will discover that the tail wheel springs do not use the riveted on tabs you describe. Instead it uses two clevis bolts instead. The only way to make this work is to remove the two riveted on tabs on the tail wheel bracket. The Scott tail wheel Bulletin I-168 covers both the Cessna 140 and 170 series aircraft.
I have a copy of the Bulletin floating around my desk at home somewhere as it came with the tail wheel springs and chains when I purchased the correct springs. But here is an attached copy for Fun


204. Tail wheel assembly
(a) Scott Model 3-24B, steerable 5 lb. (+246) (+246) (+246)
*(b) Scott Model 3200, steerable, swiveling 8 lb. (+249) (+249) (+249)
installed in accordance with Scott Bulletin I-168)

[krines]

Thanks for the diagram it appears my installation is incorrect. My eyebolts where attached to the tabs. Got to look at it again but it looks like I dont need that tab at all

[bagarre]

I'd never seen that diagram before and I've never seen a 170 set up that way.
learn something new every day.

[Metal Master]

Thanks for the diagram it appears my installation is incorrect. My eyebolts where attached to the tabs. Got to look at it again but it looks like I dont need that tab at all

That's what I did to mine. I drilled the tabs off. And installed the eye bolts. Several of the Cessna tail wheel aircraft around Auburn are set up the same way.

[krines]

Just talked to my parts man and he is having trouble finding that AN42-6 eyebolt. I must say having the eyebolt connected to both the rudder cable and tailwheel chains would make the failure of that bolt critical. As I had it installed failure of the tab only affects tailwheel steering alone and not the rudder

[bagarre]

Well, failure of the existing AN3 bolt that connects the rudder cables to the rudder horn would be just as critical.
If that breaks, it doesnt matter how your tailwheel is attached.

that and the tailwheel doesnt exactly steer on a 170 anyway.

[GAHorn]

Just talked to my parts man and he is having trouble finding that AN42-6 eyebolt. ...

Really?? Has he called one of the most prominent parts/supplier in the industry known as Aircraft Spruce? (877-477-7823)
http://www.aircraft-spruce.com/search/s ... h&search=1

an43b.jpg (2.74 KiB) Viewed 26102 times

By the way, the Cessna Parts Catalog shows the installation using the tabs...(and everyone knows how accurate that IPC is...)

I didn't find the tabs need removal to use the eyebolt, but mine uses the tabs anyway.

[Bruce Fenstermacher]

I did not need to remove the tabs on the control horn to use the Scott instructions and listed parts. I had my 170 set up this way at one time to see if there was any difference of control due to the minute change in the angle of the control chains. Didn't make any difference BTW.

[krines]

Update. Got it all fixed as per the diagram. Found the parts at Spruce as George says. Made maybe 10 landings with the new setup. On the 11th landing I was out in the middle of nowhere Montana, Missouri Breaks back country strip, 15 miles from any road. Tail wheel main leaf spring breaks (3 years old) taxiing back to park. Probably the result of the torsion caused when the original tab failed and spring chain wrapped around tail spring. First call out on 121.5 nothing. I am the bottom of 1000 foot canyon. 2nd call 30 minutes later I get USFW wolf tracking supercub. Comes to my rescue but in the interim reports me as crashed to FSS. Eventually he lands, I give him some cell numbers. 3 hours later buddy arrives with Husky tail spring set which we switch out. Definitely not the right geometry. Fly home safe. Call search and rescue and assure them I am OK. Call NTSB who was notified and they don't care. Then call FAA who was notified and explain. They seem rather concerned that A&P did not do repair. Thats when I inform them I was 15 miles from nearest road which was 15 miles to next house which was 15 miles from the thriving metropolis of Winifred MT, 300 souls. I do suggest however that I thought it would have been feasible for my A&P to ride a horse in there and fix it. Thanks for posting the link to the NASA form. Awaiting the FAA findings.

[Bruce Fenstermacher]

You know, before there were tail wheels, there were tail skids. They worked pretty well.

Something to keep in mind when your 15 miles from nearest road which was 15 miles to next house which was 15 miles from the thriving metropolis of Winifred MT, 300 souls.

[blueldr]

krines,
Wattinell were you doing flying in a metropolitan area, anyway???

[krines]

Blueldr, where the hell is Wattinell I need to fly there. Thought about the true tail dragger option but this place was rough. My spring was down in between some river rock with the rudder 1/2 inch from touching, was already bent a little bit.

[voorheesh]

Re "Awaiting the FAA findings". I am glad for you that you got your airplane out of that predicament. If you are concerned about an FAA violation, keep in mind that the FAA would have to have evidence you installed an improper part, without a mechanic certificate, returned the airplane to service, and then flew it. It could happen but is unlikely. What we all should be thinking about is how to handle a situation like this and survive it. I remember talking with Hal Terry, a noted Alaskan airman, A&P, and IA years back and he observed that if we carried every part that could fail when flying in the wild, we would not have room or weight left over for payload. But you may have to face a decision of jerry rigging the machine, losing it, or possibly losing your life unless you can get it back in the air. If a large bear or some terrorists are about to attack, I would try the tail skid or just about anything to get out of harms way. But if I am in a canyon in MT and I have radio contact with help, I have to ask what is the urgency to move the aircraft? If I can get a part flown in, why not an A&P as well? If an A&P cannot do it, can I get an A&P involved to help make sure I make the repair correctly? Can I get the installation data (such as the diagram in this post) to make sure I get it right? Anyone can turn a wrench. A good A&P either has the experience or gets the directions. Sometimes you have to wing it but most of the time you have the basis to be fairly certain you are getting it right. Hal Terry was adamant about using a qualified A&P and would not fly an "unairworthy" airplane.

I investigated an accident near Bakersfield years ago where a good pilot had an engine failure and landed on a road next to a residential neighborhood. Not an A&P, he took it upon himself to disassemble/readjust a critical component that he had no idea on how to work. Then he decided to make a takeoff because he, apparently couldn't wait to get someone qualified to make sure he had done it right. There was a takeoff accident that destroyed his airplane and I could not interview the pilot because he was on life support. Why do we make these mistakes? What impulse or necessity exists that we have to get somewhere? Anywhere?

Just a suggestion if you have to answer for installing a leaf spring with no A&P. Servicing/installing the tire of a Scott Tailwheel is within the scope of Preventive Maintenance as would be replacement of bungee cords in a ski installation, airing up a strut. A Private pilot can perform these and I would argue that installing a Scott Tailwheel is not a complex procedure and, given your predicament in that canyon, might justify your decision due to its similarity to procedures allowed by Part 43. Consultation with an A&P, even by radio, would help your case. Following Scott installation instructions would, in my opinion, result in an equal outcome to the same procedure as performed by a certificated mechanic. Using Husky parts… Well thats another story and I can't help you there. But if you show the FAA you have a clue about this and you were careful, I can't see you getting more than an intelligent discussion with the inspector. I really believe your story can help us all. A few weeks ago Arash talked about rebuilding an 0-300 under the direction of an experienced IA and related how the guy would ask him "whats next?" If Aryana didn't have his ducks in a row, that IA sent him back to the drawing board. Result: A good engine! We should think about it and fly safe