Left Aileron limited movement

[211º]

Here is my current conundrum.

I fly long cross countries about every week. About six weeks ago. I had to leave the Mooney outside in Kansas City for eight days. During this time, there wasn't any extreme weather, thunderstorms, or high winds of note (at least as far as I know).

Then, six weeks ago when I began to head back to Tuscaloosa, I did my pre-flight and everything was normal up until, I did my free and correct.

When I tested turning the control wheel to the right, everything was fine, but when I tested to the left, it felt like the control wheel did not go over as far as it normally does.

Then I looked back-and-forth to the right and the left aileron and sure enough, the left aileron did not flex upward as much as the right was doing.

I asked Tower if I could shut down and get out of the airplane to look at something while in the run-up area, and they agreed. When I got out of the plane and looked at and touched the left aileron, sure enough, it just felt like it wasn't flexing as far as it should. It also didn't feel like it was hitting a stop. It almost felt like it was pressing up against something kind mushy - but not mushy enough to press hard into it and make the aileron travel a little more.

A mechanic has removed the control rods and connections to the aileron and without anything connected to the aileron, it will flex up and down without issue (it moves freely).

So, it seems that the problem is somewhere in the control linkage between the control wheel and the rods that connect to the aileron. 

The mechanic also looked at the linkages below the cockpit and did not notice any issue (or see any debris that that might have fallen through the Johnson bar gap).

Has anyone ever had anything similar happen? With everything being "hard connected" I can't get my brain around where there might be an issue.

[McMooney]

Stupid question but PC was off ?

[takair]

Make sure the chain from the PC servos hasn’t somehow entangled or twisted. That would leave lots of tension on one side as it pulled against the servo. Would have a mushy feel. My first sugggestion was going to be right under the Johnson bar, but sounds like he looked there. Next area is where the pushrods enter the wings. 

[211º]

34 minutes ago, McMooney said:

Stupid question but PC was off ?

PC was on on the ground during runup... but it was the usual tension (and no stupid questions).

[211º]

12 minutes ago, takair said:

Make sure the chain from the PC servos hasn’t somehow entangled or twisted. That would leave lots of tension on one side as it pulled against the servo. Would have a mushy feel. My first sugggestion was going to be right under the Johnson bar, but sounds like he looked there. Next area is where the pushrods enter the wings. 

I did a "thought experiment" the other day while drifting off to sleep and I had the same thought - in my thought experiment, I even thought through that it might be the other side limiting travel. I was under the wing opening an inspection panel this evening hoping that I'd find a tangled chain, but no luck there.

[EricJ]

Yes, because it's all connected the interference could be anywhere in the control system for either side.   There's not much in the wings that'll move around to do such things, but there's a ton of stuff behind the panel.    The only time I've had a control interference issue was when a cable bundle unilaterally decided to relocate itself behind the panel and would snag on the controls behind the panel.   Took a few minutes and a zip tie or two to remedy.    Fingers crossed that yours is also an easy fix.

It's not too difficult to remove various inspection panels to get eyeballs on the bellcranks and pushrods everywhere that there could be interference.    Whatever it is should be fairly easy to spot once you get visibility to it.

[0TreeLemur]

Another pinch point is in the wing root outboard of the fuselage where the push rod travels through an area that can be congested with wires.  The left wing also has the pitot connection.  When my A&P installed the JPI OAT probe in the first inspection panel outboard from the fuselage in our C, we struggled with making sure that there was no interference with the aileron push rod.  If something came loose in that area it might impede push rod motion.  They don't just translate, they also move up/down.   Good luck!  Let us know what you learn.

[dkkim73]

With a prolonged period on the ramp, perhaps a smaller, non human aircraft enthusiast got in somehow? I don't know enough to know where such an actor might set up shop. Just a thought...

[LANCECASPER]

1 hour ago, dkkim73 said:

With a prolonged period on the ramp, perhaps a smaller, non human aircraft enthusiast got in somehow? I don't know enough to know where such an actor might set up shop. Just a thought...

Does the actor work for Disney and are his initials M. M.?

[Hank]

10 minutes ago, LANCECASPER said:

Does the actor work for Disney and are his initials M. M.?

Probably just one of his kinfolk. It's hardly nesting time for the flying ones.

[jlunseth]

I don’t understand how the PC might have an effect, but if it is chain driven, I have seen other chain driven applications where the chain rusts between two links, causing a kink in the chain. The device will have difficulty at that kink, or will stop altogether.

[LANCECASPER]

12 hours ago, 211º said:

I did a "thought experiment" the other day while drifting off to sleep and I had the same thought - in my thought experiment, I even thought through that it might be the other side limiting travel. I was under the wing opening an inspection panel this evening hoping that I'd find a tangled chain, but no luck there.

Maybe it's just age. When I get up in the morning and stretch I can't move my left aileron as well as I used to either . . lol

[Fly Boomer]

6 hours ago, dkkim73 said:

With a prolonged period on the ramp, perhaps a smaller, non human aircraft enthusiast got in somehow? I don't know enough to know where such an actor might set up shop. Just a thought...

My first thought when I read the original post.

[Jim Peace]

anything under/behind the panel blocking it?

[Pinecone]

Also remember, it doesn't have to be an issue on the left side/wing.  It could be binding the aileron down direction on the right side.

[211º]

On 1/17/2024 at 8:39 PM, EricJ said:

The only time I've had a control interference issue was when a cable bundle unilaterally decided to relocate itself behind the panel and would snag on the controls behind the panel.   Took a few minutes and a zip tie or two to remedy.    Fingers crossed that yours is also an easy fix.

I need to look up and under the panel - this might be the issue.

[211º]

On 1/19/2024 at 4:24 PM, Pinecone said:

Also remember, it doesn't have to be an issue on the left side/wing.  It could be binding the aileron down direction on the right side.

Yes - great point - it is all connected... even on the other side.

[211º]

On 1/18/2024 at 8:13 AM, jlunseth said:

have seen other chain driven applications where the chain rusts between two links, causing a kink in the chain. The device will have difficulty at that kink, or will stop altogether.

I thought that this might have been it - a kinked chain from a gust of wind or jet blast... but I didn't find that.

[211º]

On 1/18/2024 at 6:06 AM, dkkim73 said:

With a prolonged period on the ramp, perhaps a smaller, non human aircraft enthusiast got in somehow?

I thought about this and it still might be the case, but I think that the pest would have to have found its final resting location with the recent extreme cold.

[211º]

On 1/17/2024 at 10:57 PM, 0TreeLemur said:

Another pinch point is in the wing root outboard of the fuselage where the push rod travels through an area that can be congested with wires.  The left wing also has the pitot connection.

Is this visible from the small access panel in the wing or from inside the plane under the front seat's floor board?

[211º]

The next time it is above about 35ºF and free of most snow, I'm going to look up/down inside the control levers behind the panel, pull the panel under the Johnson bar and look up, and look at the wing root area.

In a perfect world, it will be able to be fixed/addressed and also be able to find the cause of the issue (not just poke around until "hey, it is all ok again").

I'll update with photos when the solution is discovered.

[0TreeLemur]

On 1/21/2024 at 10:23 AM, 211º said:

Is this visible from the small access panel in the wing or from inside the plane under the front seat's floor board?

You can see the fitment of the aileron push rod from the first inspection panel outboard from the fuselage.  You can also inspect the area where it passes under the fuselage and beneath the floor.

[cliffy]

Like Jim Peace said-  Go look under the panel to see if any wiring is blocking the movement

This is probably where the problem exists 

A skinny midget can do the job easy Most of us can't even get a look at the area

[211º]

On 1/23/2024 at 8:18 AM, 0TreeLemur said:

You can see the fitment of the aileron push rod from the first inspection panel outboard from the fuselage.  You can also inspect the area where it passes under the fuselage and beneath the floor.

So today was finally a day where I was back in KC, it was dry on the tarmac, and it was above freezing (by quite a bit today too).

I was able to view the rods after removing a panel and also able to see where the rods enter the wings.  On the RIGHT side, the rod was being "held up" or "less able to move" because of some grime build up. After removing this grime from around the rod, the LEFT aileron then went to its stop.

I didn't have the correct screw driver with me to open the near inboard access panel to look from the other side, but right now, I'm 90% confident of the problem and its fix. Tomorrow when I look from the other side, I'll be fully confident.

[0TreeLemur]

On 1/31/2024 at 6:10 PM, 211º said:

So today was finally a day where I was back in KC, it was dry on the tarmac, and it was above freezing (by quite a bit today too).

I was able to view the rods after removing a panel and also able to see where the rods enter the wings.  On the RIGHT side, the rod was being "held up" or "less able to move" because of some grime build up. After removing this grime from around the rod, the LEFT aileron then went to its stop.

I didn't have the correct screw driver with me to open the near inboard access panel to look from the other side, but right now, I'm 90% confident of the problem and its fix. Tomorrow when I look from the other side, I'll be fully confident.

Great news!  Glad the problem was not something more.