Piper Cherokee rigging question

Timbeck2

Timbeck2

Final Approach
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Timbeck2
Suffice it to say that I don't no nuttin' bout birthin' no babies, and I don't know nuttin' bout rigging my ailerons. I've had a heavy right wing since I've owned the airplane, not bad but noticeable. I've also noticed that the yoke, while flying straight and level, is slightly turned to the right and that bugs me as much as when a vehicle I'm driving's steering wheel is slightly askew when driving straight down the road.

Okay, if you go to the right wing and sight down the wing starting at the trailing edge of the wing tip, the tip, the aileron and flap are in complete alignment. If you go to the left wing and sight down the wing tip, the tip and the flap are in alignment. The aileron starts about 3/4" below the tip on the outboard edge and rises up to meet the outboard edge of the flap. The aileron in question isn't twisted or warped. It is completely straight only not in the same plane as the wing tip and the flap. I hope that makes sense.

My question is: The outboard edge of the left aileron needs to be adjusted up to bring everything into plane. In elementary terms, how is that done with just cables and rod ends? I can't visualize how that is accomplished. My mechanic and I along with an IA are going to tackle this issue within the next couple of days so no, I'm not trying to do this myself. Has anyone else had a similar issue?

Edit: one more detail I forgot, the aileron cable tension is supposed to be at 40 lbs +-5, it was around 30.
 
But Walt, I "think" in my case, the heavy wing would be caused by the left aileron being lower at the outboard edge and not in plane with the wing tip and the flap. Wouldn't lowering the flap on the right side just compensate but not solve the problem? I don't know.

I've sighted down the trailing edge of the wing on two other Cherokees and all the control surfaces are in the same plane on both wings.
 
I've read the service manual. Bellcranks and rod ends and cables...oh my! Until I can see a rod end adjustment actually move the control surface, I'm dumbfounded.
 
Timbeck2 said:
I've read the service manual. Bellcranks and rod ends and cables...oh my! Until I can see a rod end adjustment actually move the control surface, I'm dumbfounded.
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Rod end adjustment is similar to the flap adjustment but without the fancy turnbuckle doohickey.
 
Walboy said:
One fix is to slightly extend the flap on the heavy wing side. Try one turn of the turnbuckle, go fly and see if there is improvement. I have had success with that.
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The ailerons are obviously out of rig, doing that may fix the issue but increase parasitic drag. I'd fix the known issue, the ailerons. Could be a severely worn pulley on the one side, reducing cable tension, allowing for misrig.
 
The piper service manual has directions how to make the tool to check the rigging. If the shop doesn't already have one, parts over at Home Depot cost about $5.
 
Don't know 'nuthin about them Indian airplanes, but the class on rigging the Cessnas discusses making a BUNCH of measurements to make sure what you're "tweaking" is the actual PROBLEM.

Then once you know what's causing the roll rate only THEN do you start tweaking things.
 
If it's like real airplanes, its pretty simple, a couple of rig pins, a couple of turnbuckles and a rod end or two. Maybe need a protractor or rig beam.
 
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Try to find someone that knows rigging. Tweaking the aileron control system may not do much of anything except center the wheel. I suspect that the wing incidence will have to be tweaked to get rid of a heavy wing. Don't know how to do that on a Piper.
 
Adjusting the flap to trim the ailerons will get you the same thing as turning the aileron, except you wont have to turn with pressure on the aileron because it is "trimmed" (with the flap).

A heavy wing can be brought up with the rudder, which puts the ball out one way or the other. The other way is to bring the wing up with the aileron trim (flap) which gets rid of the wing low, but now you are turning. Take your pick.

Whatever you do, write down what you have done so you can undo it, because you might be making it worse. A lot of planes fly a bit wing low. I think its an effect of the prop.

Also you might not be wing low at one airspeed, but be wing low at another airspeed.
Welcome to the real world.
 
GlennAB1 said:
If it's like real airplanes, its pretty simple, a couple of rig pins, a couple of turnbuckles and a rod end or two. Maybe need a protractor or rig beam.
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According to the Cessna experts, the problem usually is that someone thinking they're "fixing" one problem, makes an adjustment, then someone later makes another adjustment to cancel that one out, and people chase their tails for years -- because you have to start with everything in a known measured position and work from there.

Of course the proper rigging instructions are available but someone always "knows this will fix it" and screws the aircraft up, and then it's a chase.
 
coloradobluesky said:
Adjusting the flap to trim the ailerons will get you the same thing as turning the aileron, except you wont have to turn with pressure on the aileron because it is "trimmed" (with the flap).

A heavy wing can be brought up with the rudder, which puts the ball out one way or the other. The other way is to bring the wing up with the aileron trim (flap) which gets rid of the wing low, but now you are turning. Take your pick.

Whatever you do, write down what you have done so you can undo it, because you might be making it worse. A lot of planes fly a bit wing low. I think its an effect of the prop.

Also you might not be wing low at one airspeed, but be wing low at another airspeed.
Welcome to the real world.
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Couple years ago I needed the rigging adjusted. Rather than the turnbuckle, the shop added a number of thin washers. Lengthy process because after each change, I had to go fly and check how it worked. The rigging tool really helps.
 
We're doing it early tomorrow morning. The IA that is coming has the tool and the know how. I guess we'll find out then.
 
My airplane flies different depending on how it is loaded. With two people and lots of gas on board it flies pretty much straight & level hands off. With just one person onbard it will slowly roll to the left, burning off gas on the left wing can help but doesn't completey null it out. I'd guess my bird was assembled either on a Monday or a Friday in 1967.
 
Well although the sight lines down the wing are not symmetrical, it is rigged properly now. I STILL don't know how it works but one half turn on one of the turnbuckles brought the cable tension into specs and the left aileron went up and the right went down a bit. Still haven't flown it yet since it is still in annual but hope to this week. I learn a lot from annuals. The IA I switched to has a good reputation here in Tucson for being not only thorough but fast. He is a self-admitted work-a-holic and loves what he does. He explained that no wing is the same and that although the wings might not be even, they are rigged properly for each particular aircraft. He also said that the crack in the wing was probably as a result of pressure over the years on the wing walk. When I told him that the crack had been there since I've owned the plane (I've been over every inch of it polishing and waxing it several times) and I though it was a scratch he told me that it isn't a big deal. We'll stop drill it and monitor it for change, no need for a scab patch for now. He's doing the AD check now and I should have a sign off early this week.
 
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Checking the rigging is a smart thing to do. Does the Cherokee not have a fixed trim tab for the aileron? Sure would be nice if our small GA aircraft had 3 axis adjustable trim tabs.
 
In the service manual you should find a drawing of a tool to properly rig the flaps. It's something easily made by any competent mechanic. Once the flaps are properly rigged the control yokes can be held in the neutral position with a straight 1X2 and some tape. Then rig the ailerons so they are in trail with the flaps.

There is one more item that should be looked at, and that is the turn coordinator. The plane must be leveled laterally when it is installed or keeping the ball centered will convey the impression of a heavy wing.
 
AKBill said:
Checking the rigging is a smart thing to do. Does the Cherokee not have a fixed trim tab for the aileron? Sure would be nice if our small GA aircraft had 3 axis adjustable trim tabs.
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The Archer II did not. -Skip
 
Norman said:
In the service manual you should find a drawing of a tool to properly rig the flaps. It's something easily made by any competent mechanic. Once the flaps are properly rigged the control yokes can be held in the neutral position with a straight 1X2 and some tape. Then rig the ailerons so they are in trail with the flaps.

There is one more item that should be looked at, and that is the turn coordinator. The plane must be leveled laterally when it is installed or keeping the ball centered will convey the impression of a heavy wing.
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Yep, I saw that and it seemed a bit confusing as to which side of the angle iron to drill the hole for the bolt. My IA had one and I saw him use it and it was a lot simpler than what I had envisioned it's use in my head. One holds it under the wing and the bolt is aligned with a rivet and the end should be parallel with the trailing edge of the flap or aileron. I thought it was supposed to be used inside the wing somehow. He had another one which looked like a rectangular aluminum piece with a slot cut into in for use inside the wing.

My problem with the heavy wing had nothing to do with the turn coordinator. I'd let go of the yoke and the right wing would slowly start to dip. I tried to use rudder trim but that just made things worse. I jacked up the wings so the spar was perfectly level and adjusted the turn coordinator to match. It didn't work. At straight and level, the ball wasn't centered. And to the other guy, no, my Cherokee doesn't have an aileron trim tab.
 
GlennAB1 said:
The ailerons are obviously out of rig, doing that may fix the issue but increase parasitic drag. I'd fix the known issue, the ailerons. Could be a severely worn pulley on the one side, reducing cable tension, allowing for misrig.
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You mean induced drag, right?
 
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