Tailwheel cables

[MontanaBird]

The '56 B model has separate cables that emerge from the tailcone that connect to the 3200 assembly. There are no chains, the end of the cable is swaged and connects directly on to the 3200. So in essence, there is no method for cable 'adjustement' on the exterior of the aircraft.

I and my heroic A&P (..here that Don?) are going to venture into the tailcone today to see what is there, and possibly reduce the slack by some means within the aircraft. I sense that it wont be easy. But hey, thats what friends are for, right?

MontanaBird

[cessna170bdriver]

The '56 B model has separate cables that emerge from the tailcone that connect to the 3200 assembly. There are no chains, the end of the cable is swaged and connects directly on to the 3200. So in essence, there is no method for cable 'adjustement' on the exterior of the aircraft.

I and my heroic A&P (..here that Don?) are going to venture into the tailcone today to see what is there, and possibly reduce the slack by some means within the aircraft. I sense that it wont be easy. But hey, thats what friends are for, right?

MontanaBird

If you have no chains, then something isn't right with your installation. The 170B IPC on pages 107A and 107B shows a clip, a short length of chain, and a tension spring between the cable and steering arm. Are you also saying you have no springs? If that's the case, you've really got something wrong; maybe the tailwheel steering cables are too long or clamped too far forward on the rudder cables inside the fuselage.

Miles

PS: The reason I thought the tension on the '55 and '56 installation might be different is that they get a straight run at the steering arm, rather than coming down from the rudder.

[lowNslow]

If you have no chains, then something isn't right with your installation. The 170B IPC on pages 107A and 107B shows a clip, a short length of chain, and a tension spring between the cable and steering arm. Are you also saying you have no springs? If that's the case, you've really got something wrong; maybe the tailwheel steering cables are too long or clamped too far forward on the rudder cables inside the fuselage.PS: The reason I thought the tension on the '55 and '56 installation might be different is that they get a straight run at the steering arm, rather than coming down from the rudder.

It also appears there is a threaded connector (Item 5, P/N 8-H) that allows for adjustment. Is this buried in the tailcone? Hard to tell from the illustration. It seems the tighter the tension the more stress you would be appling to the rear bulkhead which is prone to cracking.

[cessna170bdriver]

It also appears there is a threaded connector (Item 5, P/N 8-H) that allows for adjustment. Is this buried in the tailcone? Hard to tell from the illustration. It seems the tighter the tension the more stress you would be appling to the rear bulkhead which is prone to cracking.

That's the clamp to which I was referring. It is buried in the tailcone. It's behind the elevator belcrank bulkhead, so it isn't accessible from inside the fuselage. I would think it would be accessible through an access plate back there, but I'm not sure. Thankfully, I've never had to adjust it.

Miles

[jon s blocker]

Miles, there is no access panel to that adjustment bolt/clamp, (for the lack of a better term). I have talked to a couple of guys who made cables up, that are extra long and actualy do the adjustment clear back at the rudder. I also saw an access panel in a picture on a plane that belongs to one of the members, but it had been put there by an unknown person and not documented. The access panel would make alot of sense to be able to get into the tail cone. Seems the only way to adjust the cables is to remove the flight surfaces ! I like the idea of having a straighter shot at the rudder horns, less stress on the horns. They have a fix for the stress on the bulkhead, which is I believe a doubler at the attach points of the pulleys. Jon

[MontanaBird]

I should clarify. Yes, there is a spring, which connects to the 3200. The swaged connector is attached directly to the spring.

The 170B Type Certificate info on the 170 website indicates that the 3200 must be installed per Scott Bulletin I-168. I am going to find that, and see what it depicts.

Thnx for all the info submitted. It's great

[cessna170bdriver]

Miles, there is no access panel to that adjustment bolt/clamp, (for the lack of a better term). I have talked to a couple of guys who made cables up, that are extra long and actualy do the adjustment clear back at the rudder. I also saw an access panel in a picture on a plane that belongs to one of the members, but it had been put there by an unknown person and not documented. The access panel would make alot of sense to be able to get into the tail cone. Seems the only way to adjust the cables is to remove the flight surfaces ! I like the idea of having a straighter shot at the rudder horns, less stress on the horns. They have a fix for the stress on the bulkhead, which is I believe a doubler at the attach points of the pulleys. Jon

Unless I'm missing something (a distinct possibility ), without the tail feathers, the rudder cables would be slack, and there would be no way to accurately locate the tailwheel steering cable on the rudder cable. With the tail feathers on and rudder cables connected, it would be like building a ship in a bottle, only you can't see inside the bottle. I checked the 1963 and prior service manual, but it wasn't any help, since the 180 and 185 systems are apparently different from the 170.

Miles

[GAHorn]

...that adjustment bolt/clamp, (for the lack of a better term). ...

The cable clamps that hold one control cable to another is a common method of attaching bridle-cables (which is the common term for this sort of installation. Autopilots make extensive use of bridle-cables and clamps.)

[jon s blocker]

Miles, As I recall, I had the tail feathers off, the rudder cables in, and the complete tail wheel system in. I then adjusted the tail wheel BRIDLE cables, (thank you George), and clamped them to the length desired. To start, the rudder cables are a set length and so I put my rudder pedals in a neutral position, then went to the back and determined where to attach the bridle cable to the rudder cable. I had the tail wheel on the ground and weighted the tail down some to compensate for the lack of tail feathers plus additional weight to simulate a loaded aircraft. (This was just a guesstimate), then I attached the tail wheel cables. After the tail feathers were put on, I adjusted the tail wheel with the length of the chain as you normally do. The rudder is also adjusted at that time by the turn buckles on the cables. Hopefully that makes sense, but if not PM me or call me and I will try to do a better job of explaining it. If I were to do it again I would double the number of adjusting clamps, (peace of mind), or put on longer tail wheel system cables and make the adjustments on the outside of the fuselage. Jon

[johneeb]

Jon,
Would it be possible to add chain length until the bridle cable clamps were outside of the taicone and therefore easier to adjust?

[GAHorn]

The bridle cables are clamped inside the tail cone, and are deliberately short. The distance to the tailwheel steering arm is made up by approx. 6" of tension springs and steering chains...based purely on illustration. See Fig. 65A in the IPC.)

[jon s blocker]

We are basically restricted in what we can do physically by the slot, in the fuselage side, that the rudder cable exits from. That being said I think one could use a longer steering cable so the adjustment could be made on the outside of the tail cone and a swedge placed on the two cables near the slot so as to keep the cables close together at the slot itself. The best solution of course would be the inspection panel. Any repair of these, as far as I can tell, has to be done with the tail feathers off. For an emergency situation you can always go back to the early method of directly connecting the rudder horn and the tail wheel horn.