64’ 172E ailerons tension

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Flybo01

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Flyby30
my mechanic checked my ailerons tension and told me that one is about 20lbs loose than the others. I don’t have the airplane Mx manual, and he doesn’t have one to check the correct tension....does anyone know where can I get this info (link or manual I can buy) so my guy will have the accurate numbers?

Thnx
 
Maybe you should find a mechanic that knows how to do his job? Just sayin, him not knowing how to find it would be a pretty big warning sign to me.
 
here ya go (not a 172 but 177 '68-75 but it should be similar).....give this to your A&P.

the second one is from a '77 172....a little tighter on the tension. And just for giggles there's the 68-76 182. ;)
 

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That mechanic doesn't understand the system. He's measuring the tensions of the carrythough cable and one of the direct cables, and they will be different. You cannot adjust them separately, either, because it's a closed-loop circuit, and tightening one tightens them all.

The confusion comes about because the aileron bellcranks don't have equal-length cable arms on them. The carrythough cable arms are shorter, so that cable will show a higher tension than the direct cables, which are attached to longer arms on the bellcranks. The tension is set on the carrythough cable, which is the aft cable of the three found in the ceiling (don't confuse them with the flap cables) and it should be 30 or 40 pounds depending on model. Ignore the tensions on the direct cables.

Thing is, if he just increases the tension on that cable he throws the whole system out of rig. He needs the manual, which describes the rigging step-by-step, and it starts with locking the bellcranks and control wheels in neutral and setting the aileron pushrods first, then the cables are set. It takes a while, and I've had lots of hours correcting systems that have been "adjusted" by guys who don't read the manuals. Out-of-rig systems can make an airplane fly like a pig.

I've found aileron systems adjusted to try to correct wing-heaviness, and that doesn't work either. It's a waste of time and money. The aft wing spar attachments have eccentrics on them for that, and if they're adjusted, all the flap and aileron cables will also need resetting, because the wing spar moves in and out as the eccentrics are rotated, and that messes up all the tensions.
 
Dan since you're on here now and not to totally highjack the thread...when I'm flying ('70 Cherokee 140) trimmed straight and level, my yoke is tilted to the right about 10 degrees or so. The IA suggested adjusting the ailerons, my A&P disagrees and says to adjust the flaps. What is your opinion?
 
Hi Dan

Thnx a tone for your valuable input on this issue, just to clarify he has not gone deep into it as he is very busy with another airplane he is working on. He just asked me to bring the aircraft manual as you suggested because he needs follow this procedure step by step. The 20lbs diagnose was very superficial and he needs the manual. The problem is that I don’t have one. Now will these 3 attachments Checkout_my_six provided will work?
 
Flybo01 said:
my mechanic checked my ailerons tension and told me that one is about 20lbs loose than the others. I don’t have the airplane Mx manual, and he doesn’t have one to check the correct tension....does anyone know where can I get this info (link or manual I can buy) so my guy will have the accurate numbers?

Thnx
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Has this aircraft been flying normally?

If so,, your A&P is scamming you, he has a car payment due.
 
Tom-D said:
Has this aircraft been flying normally?

If so,, your A&P is scamming you, he has a car payment due.
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Not really I just bought the airplane and this was noted on prebuy by another mechanic I made a list of some things that need to be done. Yes I’ve flown back home and honestly can’t tell a difference since I don’t fly small airplanes for a living (this is my first aircraft)
 
Flybo01 said:
Not really I just bought the airplane and this was noted on prebuy by another mechanic I made a list of some things that need to be done. Yes I’ve flown back home and honestly can’t tell a difference since I don’t fly small airplanes for a living (this is my first aircraft)
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Cessna flight control rigging is not a one step procedure, when you really do have a discrepancy.
Take it to an A&P that will do the complete step by step procedure start to finish. by the book
 
Flybo01 said:
my mechanic checked my ailerons tension and told me that one is about 20lbs loose than the others. I don’t have the airplane Mx manual, and he doesn’t have one to check the correct tension....does anyone know where can I get this info (link or manual I can buy) so my guy will have the accurate numbers?

Thnx
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You’ll want to check the revisions on these manuals as they might not be complete/up to date.
MX manual here: https://www.redskyventures.org/doc/.../Cessna_100_Series_1962-1968_MM_D637-1-13.pdf

Parts Manual: https://www.redskyventures.org/doc/cessna-maintenance-manuals/Cessna_172_1962-73_PartsManual.pdf

Parts manuals are also available from Cessna for free, as well as service bulletins/letters. Sign up for your free account at support.cessna.com
 
yes i saw this link but when reading about the procedures, it talks about a 182 and some refer to 180 to 185 model...is this the same for a C172E model?
 
Flybo01 said:
yes i saw this link but when reading about the procedures, it talks about a 182 and some refer to 180 to 185 model...is this the same for a C172E model?
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the manual will tell you.
 
Flybo01 said:
yes i saw this link but when reading about the procedures, it talks about a 182 and some refer to 180 to 185 model...is this the same for a C172E model?
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The 182 has a very different aileron control system from a 172's. 180 and 185 are similar but have their quirks. You need the manual for your airplane. That first link posted by baboss is the one; download it, scroll down to page 6-17 and read paragraph 6-22. Back up to page 6-15 and look at Figure 6-9, and the left illustration there. It shows the aileron bellcranks and different lengths of arms that the cables pull on, which is why the tensions are different. The tension is also given there as 40 pounds at an average temperature; I would tend to set it toward the lower end of the range, as it makes the system easier to move. The tensions will be higher in hot weather and lower in cold, since the aluminum structure expands twice as much as the steel cables.

The 180 and 185's quirks? As the control column (the control "tee") moves fore and aft, the aileron cable tensions change. A lot. It's because the big aileron cable pulleys next to the column pivot aren't quite where they should have been. I set the elevator in the neutral position for rigging the ailerons, since that's where the column will be for 99% of the flight. Another one to watch for, and you should get your mechanic to look for it in your 172E, is the bulkhead under the floor that carries the aileron and manual flap cable pulleys. The tension put on the flap cables during extension puts a bunch of forward force on that bulkhead, and the stiffeners in it sometimes crack or pop their rivets, and the bulkhead gets flexible. Cable tensions are all over the map with that, because the pulleys won't stay put, and if you rig the flaps and re-check the ailerons you find the aileron tensions have dropped off a bunch. And vice-versa.
 
Timbeck2 said:
Dan since you're on here now and not to totally highjack the thread...when I'm flying ('70 Cherokee 140) trimmed straight and level, my yoke is tilted to the right about 10 degrees or so. The IA suggested adjusting the ailerons, my A&P disagrees and says to adjust the flaps. What is your opinion?
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Not a lot of experience on Cherokees, but if the manual suggests flap rigging to correct wing-heaviness, that's what needs to be done.

Now, are you holding the ailerons to the right to keep the wings level? Is the ball centered? Is the yoke 10 degrees to the right with the ball centered and hands off the controls? If it's hands-off, someone has rigged the ailerons badly, or has tried to fix wing-heaviness with ailerons, which does not work. Putting one aileron down just puts air loads on it and pushes it up until the oppposite aileron moves down until they're both down the same amount, and now there's no difference in lift to correct wing-heaviness and the yoke is cockeyed.

Make sure the turn coordinator is level in the panel. Ball-centered means nothing if it's not level, and one doesn't want to re-rig an airplane to make it fly so that the tilted instrument is satisfied.
 
A couple of informative posts by Dan, and appreciated.
 
Dan Thomas said:
Not a lot of experience on Cherokees, but if the manual suggests flap rigging to correct wing-heaviness, that's what needs to be done.

Now, are you holding the ailerons to the right to keep the wings level? Is the ball centered? Is the yoke 10 degrees to the right with the ball centered and hands off the controls? If it's hands-off, someone has rigged the ailerons badly, or has tried to fix wing-heaviness with ailerons, which does not work. Putting one aileron down just puts air loads on it and pushes it up until the oppposite aileron moves down until they're both down the same amount, and now there's no difference in lift to correct wing-heaviness and the yoke is cockeyed.

Make sure the turn coordinator is level in the panel. Ball-centered means nothing if it's not level, and one doesn't want to re-rig an airplane to make it fly so that the tilted instrument is satisfied.
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Thanks Dan. My issue is the second question: yoke 10 degree to the right, ball centered and hands off the controls. Talked to my A&P and he thinks a couple of turns extending the left flap will fix the issue. I'm glad you posted and especially your "does not work" comment because that is exactly what my mechanic said. The IA thinks differently but I know which one I trust the most and that is my A&P. Appreciate you.
 
Timbeck2 said:
Thanks Dan. My issue is the second question: yoke 10 degree to the right, ball centered and hands off the controls. Talked to my A&P and he thinks a couple of turns extending the left flap will fix the issue. I'm glad you posted and especially your "does not work" comment because that is exactly what my mechanic said. The IA thinks differently but I know which one I trust the most and that is my A&P. Appreciate you.
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I should have asked: are the ailerons streamlined with the ball centered and hands off? One isn't up and the other down? In other words, the ailerons aren't contributing any roll forces in that scenario? If so, there is no wing-heaviness and the flap doesn't need adjusting. The aileron system needs adjusting to get the yoke straight, that's all.

In a stiff aileron control system you might find that it will stay slightly set to one side and the ailerons will be deflected a bit. That shouldn't be happening; those systems should move butter-smooth and easily. These aren't dump trucks. It's amazing how much one can achieve by closely inspecting every part of the system, making sure it's properly rigged, and lubricating and freeing up all the sticky pivots, pulleys, hinges and so on. The control wheel shaft itself--that shiny chrome thing your "yoke" is attached to--acquires a sticky layer of skin oils and make it drag in the glide bearing in the panel. Clean that off with some brake cleaner and apply a bit of dry silicone lubricant spray. Never use any oil or grease of any sort. Sometimes the bearing is heavily sludged up and cleaning that can take time. But boy, it's worth it. It makes flare control in the landings so much smoother.
 
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At straight and level, the ailerons are centered on the outboard surface of the flaps but not on the wing tips. On the right side, the aileron is slightly below the wing tip, on the left the aileron is almost in inch below the wing tip.
 
I would find a mechanic that works on airplanes in a legal manner, ie. having the reference material that is required.
 
Dan Thomas said:
and lubricating and freeing up all the sticky pivots, pulleys, hinges and so on.
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kinda related . . I'll be removing the headliner for cleaning, repair and painting soon in my R182. Those pulleys that can be seen should be lubed with what? Also, is there any lube that should be applied to the cables themselves?
 
Randy Boone said:
kinda related . . I'll be removing the headliner for cleaning, repair and painting soon in my R182. Those pulleys that can be seen should be lubed with what? Also, is there any lube that should be applied to the cables themselves?
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In the center there is a cluster of small nylon pulleys. There isn't much one can do to improve their operation. They guide the flap cables and aileron balance cable across the ceiling; if they weren't there the dihedral would make the cables rub on stuff. So there's very little arc of contact on those puleys, they're tiny, they have plain sleeve bearings instead of ball bearings, and so they don't want to turn. If you lube them they might turn for a while, but the sun's heat will dry out the lube and they'll stick again. Just make sure they're clean, no grit on them, and have a real close look at the cables. Vibration makes them chatter on those pulleys and the wires wear. You'll have to twist the wires over to see the contact areas. Use a good light and look for reflections from the worn areas. Move the controls to get an idea of what sections of cable might be affected.

All other control system pulleys have small ball bearings in them. Any you see should turn easily when the controls are moved. A bit of light oil applied to their hubs can improve control feel, but if the pulleys are seized the oil will do no good. They need to come right out and get cleaned, freed up and re-lubed. If they've been worn by the cable chafing on them, they need replacing.

A 182's aileron direct cables run up the front doorposts and out through the wing's leading edge.

Cables are lubed with a sticky, waxy grease at the factory. I've never re-lubed cables, but LPS does make a chain and cable lube in an aerosol can.
 
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Thank you for the information. I'll inspect these components.
 
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