The Cessna 120-140 Association Forum

Hi folks, I need some insight / advice.

I had to remove a wing and am putting it back on and trying to get the cable tension correct. The only reference found is the Operation Manual that provides a spec of "approximately 30 pounds". What's a reasonable plus and minus? Also, on the bellcrank the control cable is 1" closer to the pivot than the carry-through cable. I don't think you can get both cables the same tension. so which cable do you measure? I'm leaning toward getting the control cables as close to 30# as I can and not worrying about the carry through other than to make sure it's not way too tight or loose. Since there's no pulleys on the carry-through cable, i don't think I have to worry about too much load on a pulley (too tight) or so loose that it jumps off a pulley.

What have others done?

Dave

I would say 30 is max. I measured the tension where the cables cross behind the pilots seat.

There is a pulley on the carry through cable, right in the center on the rear carry through spar. (I have about 50 NOS ones, if anyone needs one...)

Set the carry through cable tension not to exceed 30# and don't even measure the others. Any more tension and the ailerons will get stiff.

Thanks for everyone's responses. i hope to get past cables this weekend.

I got this information my Victor a while back as we were adjusting the tensions on my cabling during annual:

"Yes............Aileron tension. Unfortunately, the manuals are un-clear.

I would set the crossover/carrythrough cable(I believe it's the forward cable in the wing, connected to the two bellcranks) at 40lbs. That should set up the two cables that are attached to the yoke and travel through the fuselage and up into the wings at about 20lbs.
The reason for the difference in cable tension is that the Aileron bellcrank has two length arms.

Start at that point and see how the controls feel. I would not go any lower than 30lbs on the crossover cable and 15 on the two control cables that attach to the yokes. I would not go much higher than 50lbs on the crossover cable and then only if you live in AZ or someplace that is consistently warm to hot.

The ailerons should be set up this way.

Set up the cable tensions first.
Make certain that the yokes are level and can travel about 90 degrees left and right and hit the stops on the aileron bellcranks.

Once you have that correct, use the push rods from the bellcranks to the ailerons to set your travels.

I would not allow my ailerons to droop more than 1/2 inch. This gives good positive control.

If you want more speed............then set the ailerons up either neutral or actually a little high(so they "fly" and create less drag) It's a small speed improvement."