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Heavy Wing correction

Zuldarin

Well Known Member
Greetings all. I've perused the site looking for some kind of indication of which direction I need to move my aileron if I want to increase/decrease lift on one side or the other. I have a slightly heavy wing requiring full trim to fly hands off. I have followed Van's troubleshooting notes but I can't seem to find out which direction I need to move the aileron. I can't find much if any measured difference in the aileron height so I thought I would take one side and lower/raise it to increase lift on that side.

Can somebody who has made the adjustment to the hinges tell me which direction I need to move the aileron to increase lift?

Thanks,

Darin
 
Darin,

Assuming you have made your heavy wing assessment with both tanks equal and two somewhat equal mass occupants, the ball is centered and all fairings are aligned....and you still have a heavy wing, have you thought of trying a trim wedge instead of relocating the aileron hinge?

You can attach an trim wedge on the underside of one of the ailerons, which will cause it to be deflected up, thus a down ward wing heavy influence. I used double-sided carpet tape and it has worked great for 112 hrs. You can vary the affect by trimming the span wise length of the trim wedge. Most folks place the wedge behind the inboard hinge opposite the control rod.

Once you fine tune the problem, you leave the wedge in place or epoxy it in place. Re-drilling the aileron hinge is somewhat permanent and non adjustable.

I fly a 9A and if all masses are equal, it flies pretty straight and wings level. An imbalance of 5 gallons of fuel or more or single pilot ops, it will gain a heavy wing, but can be trimmed out.
 
Thanks for the information. Yes I actually do have a small trim tab on my right aileron but the inner perfectionist in me doesn't like the look of it. Even if it were not visible, I would see it. Adjusting the aileron is permanent, true, but I think that would make me feel better. I can always replace a hinge if I goof it up. :)
 
If the leading edge of an aileron is high, that wing will be "heavy". So you need to lower the leading edge of the aileron on the heavy wing. It doesn't take much. Vans sells undrilled brackets for this purpose.
 
I have a heavy left wing. I did the redrill and lowered the left aileron about 1/16" and it had absolutely no effect. I'm now flying with a wedge on the right wing and that has completely cured the problem.
 
Was it sticking up to begin with? On my -10, the right aileron was clearly (by 1/32 or 1/16"!) higher than the wing airfoil, and I was right wing heavy. Lowering that aileron removed the right wing heaviness. So I guess the answer is YMMV.
 
How can you tell?

Hi Bob, how did you measure your wing to determine that the aileron was 1/32 to 1/16 high? Did you use a straight edge on the top of the wing or the bottom? Using the Van's method is a bit confusing because if I read it correctly the tooling holes in both the wing rib and the aileron should line up but they don't...not even close.
 
Eyeballs seemed to work best for me. With ailerons in trail, I stood in front of the wing and looked down the top, aft third of the wing to the aileron. On the right wing the transition was smooth, on the left there was a little "step up" at the aileron. A straight edge confirmed this but I felt my eyeball was a bit better at seeing this. BTW, it was only the outboard bracket, not the inboard one.
 
I have a heavy left wing. I did the redrill and lowered the left aileron about 1/16" and it had absolutely no effect. I'm now flying with a wedge on the right wing and that has completely cured the problem.

Same here on my 6. I observed a bit of wing twist on my left wing while setting the incidence and I believe this twist and ultimate incidence difference between left and right is causing my heavy left wing (further evidenced by the dropping left wing in a stall). However, I tried all of the different methods discussed on this site, as they are all preferable remedies to a trim tab. My learning from all of that was that there are several causes of wing heaviness and different remedies for each.

Larry
 
Heavy wing

You can also squeeze down the trailing edge radius of the light wing's aileron. (double check me on this.. I think it's the light wing if I remember correctly). This is addressed in the builders manual. I learned the hard way after installing rebuilt ailerons on my 4 without squeezing down the trailing edges to the proper radius. Almost could not control the roll once I got airborne, and to put it lightly it was a eye opening experience! This is called "aileron snap", and not being the builder I was completely unaware of this.
Long story short... It makes a big difference simply by slight squeezing of the trailing edge of the aileron.
 
You can also squeeze down the trailing edge radius of the light wing's aileron. (double check me on this.. I think it's the light wing if I remember correctly). This is addressed in the builders manual. I learned the hard way after installing rebuilt ailerons on my 4 without squeezing down the trailing edges to the proper radius. Almost could not control the roll once I got airborne, and to put it lightly it was a eye opening experience! This is called "aileron snap", and not being the builder I was completely unaware of this.
Long story short... It makes a big difference simply by slight squeezing of the trailing edge of the aileron.

A good data point and an important step. However, the 9&10 use riveted trailing edges and are not raidused and nonadjustable.
 
A couple turns on a flap actuator rod can have a pretty significant difference too. It's really hard to build an 8ft flap without a little bit of twist, so even if your ailerons and flaps line up, your flap position could be part of the problem. It addressed most of my heavy wing.
 
Heavy wing

I have cured several airplanes including my 9A with a couple of turns on the flap push rod. Lower the flap on the heavy wing side and it does work within reason. Major problems with a heavy wing may require more bold actions.
 
Heavy left wing

Looking for a little help in that after installing a new AutoPilot (two axis) I have a very heavy left wing? Has anyone experienced this type of thing. My A&P actually installed it for me, I didn't have this before the installation?
Thanks for the help.
 
A couple turns on a flap actuator rod can have a pretty significant difference too. It's really hard to build an 8ft flap without a little bit of twist, so even if your ailerons and flaps line up, your flap position could be part of the problem. It addressed most of my heavy wing.

my heavy wing was the flap. set the flap to the wing not the fuse.
 
Looking for a little help in that after installing a new AutoPilot (two axis) I have a very heavy left wing? Has anyone experienced this type of thing. My A&P actually installed it for me, I didn't have this before the installation?
Thanks for the help.

If the wing was not heavy before installing he roll servo, then the aileron rigging was screwed up when the servo was installed.

Rig the ailerons.

Carl
 
Heavy wing

Sure sounds like the aileron rigging got fouled up during the AP install. Go back and re-rig the ailerons starting withe aileron rigging fixture (Stick). After that you can redo the AP servos.
:(
 
Aileron hinge bracket

I found out that Vans doesn't offer a blank hinge bracket for the RV9.
They said they do have one for the 6 model but I would need to do some trimming to make it fit the 9. Has anyone tried to make a blank aileron hinge bracket for the 6 work for the 9? If so what is the difference and what do you have to do to make it work?

Thanks
Jim
 
Simple

I did this for one bracket on my 9A. Adjust the hole position relative to the rod end bearing bolt hole and drill the first hole, raise or lower the hole by the desired amount. Then use the original bracket as a drill jig for the other hole. The bracket is longer than the original 9 bracket, so just use the original bracket profile to trim the new one to match. Prime and paint.
 
Is it possible to weld these holes closed on the existing bracket and re-drill them? It has been some time since I did these but seem to remember they were steel(chrome-moly)? That is my recollection.
 
which aileron bracket?

My newly aquired 9A has a heavy left wing..so much the trim wont relieve it.
after much measuring and consternation, I believe the wings are very close to the same incidence, about .3 degrees averaged over 6 places. (3 tenths)
There is a twist in the right side aileron, its 1/2 inch high on the outboard end when the inboard is held even with the trailing edge of the flap. hmm..a little upward bow in the trailing edge of it also. adjusting the left flap down 3 degrees farther than the right side takes the pressure off. Dont like this solution. aircraft rides rougher.
now..in regards to the ailerons, they are BOTH quite a bit higher at the leading edge than the wing. when I lay a straight edge across the wing and aileron, there is quite a gap..over a quarter inch at the wing just in front of the aileron.
A close examination of the fiberglass tip..the right side tip has an pretty good dish in the underside trailing edge, with the trailing edge low.

In examining the ailerons, and reading the solutions offered here, its not clear to me just which hole should be slotted, or redrilled, or whatever. Is it in the thin pieces on the aileron, or in the heavier bracket that is riveted to the wing?
 
Since you didn't build the airplane there are some details you would not be aware of that are important to know when working on rigging / trim.

- Checking alignment of ailerons to flaps or wing tips is of little value when it is unknown if the tips are correctly positioned or whether the flaps have any twist in them. The best way to check for twist in flaps and ailerons (any control surface for that matter) is with a digital level. restrain the surface so it can't move and check with the level on the flat portion at each end.

- It is normal for the ailerons to appear bulged outside of the profile of the wing. They are designed to be slightly larger than a nominal shape would be if you just extended the shape profile of the wing. This helps maintain good flow attachment on the aileron.
A 1/4 gap sounds excessive though. This could be caused by the top skin not laying where it should. This is caused by the top flange on the rear spar not being at the correct bend angle.
 
9A aileron alignment

On my 9A one of the wingtips is not quite properly aligned, a little low to trailing edge. That affects wings level flight. Ailerons are just where they should be.
 
flaps

Thanks for the reply Steve.
The Flaps definitively are not in alignment now with the fuse. Prior to my adjustment, they were even with the fuse at the root..both the same..no gap. now..the left flap after I adjusted it far enough to take the pressure off the stick..is about 3/4 inch lower at the trailing edge next to the fuse. This equated to a 3 degree increase on my Stabila digital level.
IN regards to being aligned with the wings. Not sure where to reference.
Should the top of the flaps when retracted (full up) be perfectly level with the top of the wing? (which has a bit of a dip in the last foot of airfoil)

when I lay a 4 ft level across the aileron and flap,, and I pull the aileron to match the bottom of the level, the leading edge of the aileron is high enough that the level does not touch the wing for about a foot, with the gap under it better than a 1/4 inch at the trailing edge of the wing.

I dont have the blueprints for this craft btw, the builder passed away before I got them..about two weeks after I bought it. I have the builders manual, the builders photo log, and the aircraft logs..still hoping the widow finds the prints.
 
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I dont have the blueprints for this craft btw, the builder passed away before I got them..about two weeks after I bought it. I have the builders manual, the builders photo log, and the aircraft logs..still hoping the widow finds the prints.

I suggest you start with getting a copy of the plans and manual. It is available from Van's in digital format on a USB drive for $10.

Then start from the outboard end aligning the ailerons with the main wing as described in the plans (this will require removing the wing tips). Then work inboard from the outboard end of the aileron looking for twist and misalignment between the ailerons, flaps and fuselage.
 
10 Bucks?..OMG..I'll order those tomorrow!
Thanks! I was afraid they would want 500 dollars!
 
Importance of aileron trailing edge raduius!

Excellent advice above to assure effective coponents are working together properly. That said, i recently posted re: RV3 that I was able to transition from C172!aileron feel to fingertip rolls just due to aileron traling edge radius. Just another datapoint for your quest !
 
Thanks for the reply Steve.
The Flaps definitively are not in alignment now with the fuse. Prior to my adjustment, they were even with the fuse at the root..both the same..no gap. now..the left flap after I adjusted it far enough to take the pressure off the stick..is about 3/4 inch lower at the trailing edge next to the fuse. This equated to a 3 degree increase on my Stabila digital level.
IN regards to being aligned with the wings. Not sure where to reference.
Should the top of the flaps when retracted (full up) be perfectly level with the top of the wing? (which has a bit of a dip in the last foot of airfoil)

when I lay a 4 ft level across the aileron and flap,, and I pull the aileron to match the bottom of the level, the leading edge of the aileron is high enough that the level does not touch the wing for about a foot, with the gap under it better than a 1/4 inch at the trailing edge of the wing.

I dont have the blueprints for this craft btw, the builder passed away before I got them..about two weeks after I bought it. I have the builders manual, the builders photo log, and the aircraft logs..still hoping the widow finds the prints.

the method I used was to measure with a scale from the aft edge of the flap to a rivet line on the wing. make both sides the same. crude but effective. a friend advised me of this method after several unsuccessful attempts to correct the heavy wing.
 
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Excellent advice above to assure effective coponents are working together properly. That said, i recently posted re: RV3 that I was able to transition from C172!aileron feel to fingertip rolls just due to aileron traling edge radius. Just another datapoint for your quest !

An RV-9 has riveted ailerons with trailing edges that are constructed totally different than your RV-3 so it is not possible to adjust them like many of the other RV's.
 
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