Video - How to have a ground loop

Oh no, it wasnt the leaf spring! It was one of the springs between the rudder and tailwheel control horns. Not as serious, but bad enough to make trouble for a newbie.
Fearless Tower said:
That's what I meant about being worn out....the springs don't have an indefinite life and if they wear out they will break.
Click to expand...
 
rottydaddy said:
Oh no, it wasnt the leaf spring! It was one of the springs between the rudder and tailwheel control horns. Not as serious, but bad enough to make trouble for a newbie.
Click to expand...

Never heard of one of the actual springs breaking. Guess that could happen, though. Most are compression springs and very heavy duty compared to the other connecting hardware. Much more fragile and prone to breaking are the chain links and "paper clips" that connect these springs to the horns on the tailwheel and rudder. They are very thin and will wallow out and eventually break. Have a buddy who wrecked his Pitts because of this. Inspect these on preflight. They're so inexpensive that you might as well just replace the chain links and clips at each annual as cheap insurance. Also a good idea to safety wire the "paper clips" to keep them from coming apart.
 
whifferdill said:
Most are compression springs and very heavy duty compared to the other connecting hardware.
Click to expand...
Are most compression springs?

I know the 170 with the 3200 is specifically NOT supposed to have compression springs and compression springs if used can actually cause damage.
 
Fearless Tower said:
Are most compression springs?

I know the 170 with the 3200 is specifically NOT supposed to have compression springs and compression springs if used can actually cause damage.
Click to expand...

Curious why? I don't know the breakdown or what planes can only use (and why) one or the other. I have seen many more compression than tension springs on the tailwheels planes I've hung around and flown. If you have a choice, you should use compression springs for several reasons. Compression springs in their unactivated state, or when the rudder is neutral, are not applying any force on the tailwheel. They only apply force when the rudder is moved left or right, and then only on the side of desired movement. Tension springs, on the other hand, apply tension all the time, so if one breaks, (they are not as beefy and are more likely to break) the broken side whips free and the tension on the other side pulls the tailwheel to the side. Not good at critical points of a landing or while taxiing. Compression springs also give better handling. When you are taxiing with a tension spring, and you push rudder, it stretches the spring and the wheel thinks about moving then responds, in a springy sort of way. When you do the same with compression springs, the response is tight and immediate, which means as pilot and operator, you get immediate feedback as to whether you need more or less rudder input; you don't have to wait and see what will happen. Also, compression springs are typically thicker. Thicker metal outlasts thinner metal every time.
 
Last edited:
BillTIZ said:
First thing I check is tire pressure. Normally it is low. Tire shimmy alone should not cause loss of failure to maintain centerline. Something else is going on. He was drifting to the right side of the runway on landing. It looks like he over corrected trying to correct back and keep it on the runway.
Click to expand...

Yea I was going to say something about the centerline not being in service.
 
whifferdill said:
Curious why? I don't know the breakdown or what planes can only use (and why) one or the other. I have seen many more compression than tension springs on the tailwheels planes I've hung around and flown. If you have a choice, you should use compression springs for several reasons. Compression springs in their unactivated state, or when the rudder is neutral, are not applying any force on the tailwheel. They only apply force when the rudder is moved left or right, and then only on the side of desired movement. Tension springs, on the other hand, apply tension all the time, so if one breaks, (they are not as beefy and are more likely to break) the broken side whips free and the tension on the other side pulls the tailwheel to the side. Not good at critical points of a landing or while taxiing. Compression springs also give better handling. When you are taxiing with a tension spring, and you push rudder, it stretches the spring and the wheel thinks about moving then responds, in a springy sort of way. When you do the same with compression springs, the response is tight and immediate, which means as pilot and operator, you get immediate feedback as to whether you need more or less rudder input; you don't have to wait and see what will happen. Also, compression springs are typically thicker. Thicker metal outlasts thinner metal every time.
Click to expand...
Compression springs are certainly beafier, but the problem in the 170 as I understand it is that when the compression spring is compressed, it becomes solid with no give. The result in the 170 can be tearing the rudder cable pulleys off of the bulkhead.

From what I have heard, this is not a problem for some other aircraft like Maules. What happens with the 170 is that people who do not know differently install them thinking it will correct the sloppy stearing. Problem is the stearing is the way it is because that is how it was designed. They say that the stearing is the only reason Cessna put brakes on them.
 
rottydaddy said:
Oh no, it wasnt the leaf spring! It was one of the springs between the rudder and tailwheel control horns. Not as serious, but bad enough to make trouble for a newbie.
Click to expand...

Do you have tension springs or compression springs ?
 
Fearless Tower said:
The result in the 170 can be tearing the rudder cable pulleys off of the bulkhead
Click to expand...

The 170 and 172 have no pulleys in the rudder cable system. either spring type is acceptable, use what is given in the IPB.
 
Tom-D said:
The 170 and 172 have no pulleys in the rudder cable system. either spring type is acceptable, use what is given in the IPB.
Click to expand...
Interesting to hear that.....so what were the photos of that George Horn posted on the 170 board?
 
Fearless Tower said:
Compression springs are certainly beafier, but the problem in the 170 as I understand it is that when the compression spring is compressed, it becomes solid with no give. The result in the 170 can be tearing the rudder cable pulleys off of the bulkhead.

From what I have heard, this is not a problem for some other aircraft like Maules. What happens with the 170 is that people who do not know differently install them thinking it will correct the sloppy stearing. Problem is the stearing is the way it is because that is how it was designed. They say that the stearing is the only reason Cessna put brakes on them.
Click to expand...

the 120/140/170/180/185 with Scott assemblies will kick out and caster at 35 degrees then the rudder will go all the way forward and not over extend the Scott arms that control the assembly.

The stiffer springs only allows better control of the 35 degrees left or right of center. and gives you the ability to stop a turn before the tailwheel kicks out and the assembly goes into caster mode.
 
Fearless Tower said:
Interesting to hear that.....so what were the photos of that George Horn posted on the 170 board?
Click to expand...

I have no clue as to what George posted any where. get a IPB for the 170 and see for your self.

There are 6 part numbers in figure 45 that are called pulleys, but they are used as shivs to guide the rudder cables and take no tension on them.
 
Last edited:
Fearless Tower said:
That's what I meant about being worn out....the springs don't have an indefinite life and if they wear out they will break.
Click to expand...

Here's our tailwheel leaf spring. Directional control was harder after it broke.
 

Attachments

  • Tailwheel leaf sping 2 (1335 x 528).jpg
    Tailwheel leaf sping 2 (1335 x 528).jpg
    224 KB · Views: 12
Was weight in the cockpit listed as a contributing factor?

Diana said:
Here's our tailwheel leaf spring. Directional control was harder after it broke.
Click to expand...
 
wabower said:
Was weight in the cockpit listed as a contributing factor?
Click to expand...
Well, the female weight in the back was wondering what the male weight in the front was doing as the airplane departed the asphalt. ;)
 
Then it's safe to assume we can forego any further discussions of dead weight?:D

Diana said:
Well, the female weight in the back was wondering what the male weight in the front was doing as the airplane departed the asphalt. ;)
Click to expand...
 
You must log in or register to reply here.
Back
Top