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Aileron squeezing

P

petersb

Well Known Member
I have a left wing heavy situation, the left aileron is flying about 3/8 inch low for level flight. All control surfaces are aligned accurately with tooling holes in outside rib.

Question , if the light aileron is squeezed to correct this problem will the ailerons still be out of alignment, that is the left aileron will still be 3/8 inch low.

My thoughts are the left aileron is low to compensate for less lift on the left wing and therefore squeezing the right aileron will simply maintain the same aileron flying positions without the need for control stick pressure

Comments please

Peter
 
Look at the advice on the Vans site carefully

My recommendation is that you look at the relative alignment of the L&R ailerons relative to the wing at the outboard hinge area. Van's sells hinge brackets without pre-drilled holes and describes a procedure to fix the heavy wing this way as a first step. I did this with mine and the results were great. Squeezing is not the first resort IMHO.

Vans Link: http://www.vansaircraft.com/public/construction-faq.htm

open the "Wing Heavy Analysis" .pdf near the bottom of the page and follow the guidance there...

Good Luck and enjoy the ride...:)
 
Thanks for the response Terry. What I am really interested in knowing is, do the ailerons align with the trailing edge after an aileron squeeze has corrected the heavy wing condition.

Peter
 
Rigging and twist...

If the ailerons are mis-aligned when you are flying straight and level (using stick force) then squeezing them will only relieve the stick force and you have a rigging issue, wing twist, or some other issue...

Squeezing a trailing edge should only be done after ensuring that all rigging, twist, or other build issues are corrected and the plane is flying straight ... it only relives aileron stick force and is not a cure all.

The perceived 3/8 mis-alignment of the aileron is relative to what? It might be the trailing edge of the wingtip that is mis-aligned and needs adjustment or the flap could be off, or has a twist, perhaps the aileron has a twist...
 
[email protected] said:
If the ailerons are mis-aligned when you are flying straight and level (using stick force) then squeezing them will only relieve the stick force and you have a rigging issue, wing twist, or some other issue...

Squeezing a trailing edge should only be done after ensuring that all rigging, twist, or other build issues are corrected and the plane is flying straight ... it only relives aileron stick force and is not a cure all.

The perceived 3/8 mis-alignment of the aileron is relative to what? It might be the trailing edge of the wingtip that is mis-aligned and needs adjustment or the flap could be off, or has a twist, perhaps the aileron has a twist...
Click to expand...

Stephen, thanks, that is what I was thinking, only the stick forces are releved

The fibreglass tips where lined up with the rib tooling holes then the ailerons and flaps to the tips. Not too worried yet as I am only 5 hours into phase1, have read all the info on the forum in this regard, however nowhere is it mentioned if the ailerons lineup after the squeeze, now I know, thanks

Peter
 
The tips are last.

Ailerons get aligned with the tooling holes, followed by the flaps to the aileron. Only then can you install the tips...and they may be out of alignment by a fair amount. But are easy to adjust.
 
Ailerons to tooling holes...

Not sure how you can accurately align the tip to the tooling hole... The control surface should be aligned to the tooling hole, then the tip is fitted to match the aileron.

Hey Brian, you are beat me to it ;)
 
They did on mine.

-John

petersb said:
Thanks for the response Terry. What I am really interested in knowing is, do the ailerons align with the trailing edge after an aileron squeeze has corrected the heavy wing condition.

Peter
Click to expand...
 
boomer said:
They did on mine.

-John
Click to expand...

John, I have only just started looking at the problem. So far ailerons,flaps and fibreglass tips are all aligned when stationary. There is no change in the 3/8 inch low left aileron position regardless of speed 100 to 170 mph.
The vertical position of ailerons relative to the rear spar looks good.

Tried flap adjustment without effect. Filled right tank to 60 litres, left 20 litres, no effect.

Any body else squeeze ailerons to correct heavy wing and also end up with the ailerons, flaps, tips line up ?

Peter
 
I maintain an 9A that had a wing heavy condition. Everything was rigged perfect. Just the nature of the build. We corrected it with a small wedge temporally taped to the aileron. adjusted the length of the wedge to get 0 control input. I will get the supplier of the wedge. and post it tomorrow. I don't like bending straight controls.
 
Mummy16 said:
I maintain an 9A that had a wing heavy condition. Everything was rigged perfect. Just the nature of the build. We corrected it with a small wedge temporally taped to the aileron. adjusted the length of the wedge to get 0 control input. I will get the supplier of the wedge. and post it tomorrow. I don't like bending straight controls.
Click to expand...

Thanks for the reply, I am trying to correct the wing heavy situation and end up with tips, ailerons and flaps lined up.

Peter
 
Have you gone through the Van's "Heavy Wing Procedure" from beginning to end? That's really the way to tackle the issue.

Last step is squeezing aileron trailing edges.
 
Aileron hinge

I had a heavy wing and went through Van's trouble guide. I found the outboard aileron hinge point on the heavy wing allowed the aileron to sit higher than the other wing.

I slotted the holes and shifted the hinge point and flew, and heavy wing was better but not fixed. Slotted a bit more and shifted the hinge down maybe 1/32 more, test flew and no heavy wing any more.

If you look at the DWG of the aileron hinge and draw some tangent line to the wing skin to the top of the aileron, you will see that there should be about 1/32 of daylight between the straight line and the top of the skin. This DWG is to full scale. When I put a ruler on the wing skin so it rested on the top of the aileron when it was aligned per the rigging my right aileron (heavy wing) sat 3/32 high, the right was perfect. Also check the inboard aileron hinges.

Had a local guy fly for the first time in his RV-7 and I noted he had the same "high aileron hinge" This predicted his heavy wing issue.

I did not like the idea of trying to match slotted holes to a blank bracket. I have flown mine with the slotted holes and the hinge has not moved. I plan to drill for a rivet between the two bolts when I take the wingtip off at annual, which I am in the process of beginning. 175+ hours so far!

Cheers
 
RVG8tor said:
I had a heavy wing and went through Van's trouble guide. I found the outboard aileron hinge point on the heavy wing allowed the aileron to sit higher than the other wing.

I slotted the holes and shifted the hinge point and flew, and heavy wing was better but not fixed. Slotted a bit more and shifted the hinge down maybe 1/32 more, test flew and no heavy wing any more.

If you look at the DWG of the aileron hinge and draw some tangent line to the wing skin to the top of the aileron, you will see that there should be about 1/32 of daylight between the straight line and the top of the skin. This DWG is to full scale. When I put a ruler on the wing skin so it rested on the top of the aileron when it was aligned per the rigging my right aileron (heavy wing) sat 3/32 high, the right was perfect. Also check the inboard aileron hinges.

Had a local guy fly for the first time in his RV-7 and I noted he had the same "high aileron hinge" This predicted his heavy wing issue.

I did not like the idea of trying to match slotted holes to a blank bracket. I have flown mine with the slotted holes and the hinge has not moved. I plan to drill for a rivet between the two bolts when I take the wingtip off at annual, which I am in the process of beginning. 175+ hours so far!

Cheers
Click to expand...

Mike, thanks for the input. On first inspection ie: a ruler from the top of the aileron onto the wing skin it seems correct, however, I will take a closer look.

Regards. Peter
 
If you're flying with the ball centered but you must deflect the ailerons to fly straight and level something isn't rigged correctly. I'm surprised it is deflected the same amount over a wide speed range.

I would check everything again...everything.
pants and fairings on or off?
wing sweep & incidence?
HS & VS installed correctly?
Twist in any controls surface?


I had a very heavy left wing. But flew straight and level when everything was lined up. When I relaxed pressure on the stick it would roll left. the faster I went the harder it rolled. It was scary over 170kts. When I let go of the stick the left aileron would deflect upward a lot. I never quantified the amount of deflection, as I was busy trying to stay upright. I found my outboard aileron hinge was causing the aileron to stick above the wing skin. Dropping the hinge <1/16" fixed it.
Separate issue was unstable in roll axis. I squeezed both sides a touch and this went away too.
 
hydroguy2 said:
If you're flying with the ball centered but you must deflect the ailerons to fly straight and level something isn't rigged correctly. I'm surprised it is deflected the same amount over a wide speed range.

I would check everything again...everything.
pants and fairings on or off?
wing sweep & incidence?
HS & VS installed correctly?
Twist in any controls surface?


I had a very heavy left wing. But flew straight and level when everything was lined up. When I relaxed pressure on the stick it would roll left. the faster I went the harder it rolled. It was scary over 170kts. When I let go of the stick the left aileron would deflect upward a lot. I never quantified the amount of deflection, as I was busy trying to stay upright. I found my outboard aileron hinge was causing the aileron to stick above the wing skin. Dropping the hinge <1/16" fixed it.
Separate issue was unstable in roll axis. I squeezed both sides a touch and this went away too.
Click to expand...

Brian

Seems your plane would fly level when the aileron was centered, the high hinge would drive the aileron up when you released the stick, if I read you correctly. In my case the plane rolls to the left if the aileron is held in alignment, it requires the 3/8 inch low deflection to maintain level flight.

With this in mind it seems the out of vertical hinge position drives aileron position which causes the roll
 
My wing wasn't too heavy, but just enough so that I could not trim it out with my electric trim. At cruise, one aileron was about 1/4" above its wing tip and the other was about 1/4" below. If I remember correctly, it took me about 10 phase 1 flights to correct the problem. Here's what worked (finally) for me. Your mileage may vary.

First, I downloaded and followed Vans heavy wing instructions.

After checking the rigging, I tried an extra turn or two on the aileron bell cranks, but this did not help, so I went back to my original rigging. I then started squeezing one aileron. I tried all the hand squeezing techniques in the Van's instructions with very little effect. I finally got out my hand seamer and used it with some duct tape inside the jaws. I used VERY LIGHT forces and took about three flights to get enough squeeze to be effective. In fact, the last squeeze made the other aileron slightly heavy, but finger squeezing put that right, and I ended up with no heavy aileron and both ailerons aligned with the wing tips in flight. Hopefully you will not have to go the hand seamer, but, if you do, be careful and work slowly.

The bottom line is to follow Van's instructions and go slowly. And make sure the ball is centered before doing anything else!

-John

petersb said:
John, I have only just started looking at the problem. So far ailerons,flaps and fibreglass tips are all aligned when stationary. There is no change in the 3/8 inch low left aileron position regardless of speed 100 to 170 mph.
The vertical position of ailerons relative to the rear spar looks good.

Tried flap adjustment without effect. Filled right tank to 60 litres, left 20 litres, no effect.

Any body else squeeze ailerons to correct heavy wing and also end up with the ailerons, flaps, tips line up ?

Peter
Click to expand...
 
Ball in the middle

Several posters have correctly mentioned that the ball must be in the middle when doing these tests in flight.

That assumes that your slip indicator (ball) was properly calibrated when the instrument was installed in the panel. Hopefully, the aircraft was carefully leveled laterally (roll axis) on jacks, and the indicator was rotated a bit clockwise and counter-clockwise until the ball was exactly in the center before being tightened down in the panel.

If you didn't do this when installing the slip indicator, then you will not know when the ball is truly centered, and might be actually inducing a problem.
 
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