Rudder Cables

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

Post Reply
User avatar
wa4jr
Posts: 437
Joined: Mon Apr 29, 2002 2:44 am

Rudder Cables

Post by wa4jr »

I received the results of the pre-purchase inspection on the '54 170B that I am about to purchase. Most everything is fine, but the mechanic flagged the rudder cables as having a problem. He says that with no foot pressure on the left rudder pedal, the pedal falls back toward the cabin and the left rudder cable drops onto the aircraft belly. Right rudder cable is fine. With feet on the pedals, rigging seems fine and rudder action good. He says that there is usually a spring forward of the rudder pedals that maintains proper tension on the cables, but he can find no spring.

The present owner lowered the price and I am going to instruct the A&P to pull the cables and inspect them, since he found a broken strand on the left cable. The A&P is not a 170 man, so any help regarding the proper tension on the rudder cables, and how this tension is applied, would be greatly appreciated.

With any luck, next month I will receive my taildragger signoff after 10,500 hours of flight time, and begin the trek from southern Alabama to northern Virginia in my first....and hopefully last Cessna 170 :D
John, 2734C in Summit Point, WV
User avatar
GAHorn
Posts: 20967
Joined: Fri Apr 12, 2002 8:45 pm

rudder circuit cables/springs

Post by GAHorn »

You are correct to have the cables thoroughly inspected. (And don't forget all the cables that pass thru the rearmost bulkhead....things are blind back there and can usually only be inspected by pulling them out.)
The only tension upon the rudder cables is placed there by the rudder return springs, one of which appears missing on yours. If you decide to buy the plane, have the mechanic completely disable and remove the parking brake system, "Y", levers, etc from the tops of the master cylinders and front of the rudder pedal area. (You can leave the parking brake pull cable to the panel in place, for appearances.) The parking brake system can foul the firewall blanket in strong crosswinds and lock your brakes for you inadvertently just before landing, setting you up for a blown tire and groundloop.
User avatar
Roesbery
Posts: 302
Joined: Tue Apr 23, 2002 4:34 am

Post by Roesbery »

You can access the springs through the holes in the forward part of the tunnel, and from inspection covers on the belly. They are a real pain to install but if you remove any burrs on the spring ends and do a little fileing to make a slight point they will slip into the holes with a bit less cussing than might be done otherwise.
Post Reply