Inherent right roll

[Graham Kerr]

My RV-3A, N555RV has a built in right roll. Which requires a a constant 1/2 pound left stick pressure to overcome. If I take my hand off the stick it will roll right at about 50 degrees per second. I have inspected and tightened the friction on the mechanical trim with little effect. The airplane has always had this tendency. During my last condition inspection my A&P during the process of borescoping the wing spar, installed a square inspection port on the lower side of the wings slightly outboard of the wheel pants so he could better see some suspect areas on the spars (turned out to be scratches not cracks, thank goodness). Since then the roll tendency seems worse. Can the aileron pushrods be adjusted to fix this!
Cheers
Graham

[DeeCee 57]

No, pushrod length won’t help.
Heavy wing is cured by altering the trailing edge of the aileron, usually one side, by squeezing it, again usually done with a bending brake.
Reference to be found in the Rvator and here on VAF

Love that call sign of yours...

[Mel]

Apply duct tape to seaming plier jaws (to prevent scratches) and gently squeeze the trailing edge of the left aileron. Do this in very small increments. A little bit goes a long way.

[Carl Froehlich]

Before you go squeezing trailing edges, here is my recent post on rigging. I would first suspect an aileron (or both) hanging high or low.

Carl

My suggestion:
- Start with the flaps. Make sure they are really all the way up (common problem) by a straight edge on the bottom of the fuselage. Once done, run a straight edge along the flap length to check for twist and to make sure left and right flaps are exactly how the same.
- Once flaps are set, then rig the ailerons to be in a straight line with the flaps. Both sides the same, stick in the right position. Do this with the elevator clamped in neutral.
- Again with a straight edge verify the ailerons have not twist and left and right are the same.
- With ailerons clamped to the flaps in the up position, measure the wing skin to aileron leading edge gap. You are checking to make sure you don?t have one end lower/higher than the other. This I find is the leading cause of the dreaded heavy wing.
- After all this is done, then move on to the wingtips. As yours are already done, if they are not aligned with the ailerons you may need to rework. If they are just a little off then fly the plane before making the decision to rework or not.

Rigging is not one and done. Take your time and have an extra set of eyes. It pays off.

[rvbuilder2002]

There are different ways to correct a roll trim issue but before doing any of them the ailerons should be evaluated for proper build/shape.
It makes no sense to jump to one method without first confirming Whether something else is causing it. It is commonly aileron shape. That is why it is often the first thing recommended.
Refer to Section 5 in the manual and use the instructions to evaluate the aileron shape. If they are correct, THEN move on to something else.

[FinnFlyer]

Is this new to your airplane? Did it fly straight before?

Also check gear leg fairings (and wheel pants).

Finn

[Graham Kerr]

To all who replied above: Thanks so much for your info. I've been out of pocket for a few days but am now back. Intend to start with the simplest and work through the process you've outlined until I get a good result. I'll keep you posted.
Sremper Fi
Graham

[Larry DeCamp]

Once you do that, you will have an aileron that is stiffer (less effective) and not realistically reversible if there is another problem. Follow Carl?s protocol. There is a lot of info on the forum also.
START HERE :
Take a straw, dowel , small bent angle of .032 al or whatever),any thing to tape on the bottom of an aileron. Start short and increase length / height until you get the wing lifted.
THEN, you can explore other misalignments ( hinge height etc) and simply tape it back on to fly straight while you analyze. The subject.
Google Dan Gurney ( Gurney Flap) to get idea where to start and why it works. Call me if you want confer Larry 765 505 1160
Dont smash the trailing edge, I have two you can have if you want Stiff , less effective ailerons.

[rv3pilot]

Originally Posted by Graham Kerr

My RV-3A, N555RV has a built in right roll. Which requires a a constant 1/2 pound left stick pressure to overcome. If I take my hand off the stick it will roll right at about 50 degrees per second.
Cheers
Graham

I had the exact same problem. There is an aileron trim tab on the right aileron that was NEVER adjusted. I "tweaked" it slightly and I now have no roll tendency. If I didn't have the trim tab, I would adjust the trailing edge of the left aileron.

http://www.vansairforce.com/communit...t=1747&page=13

The second picture.

Chris

[DTARM1]

You actually fly an airplane that rolls 50 degrees per second if you don't put pressure on the stick to counteract the roll?

1) Aileron control surfaces or trim tab are/is out of wack (use a digital protractor)
2) Aileron cable tensions are out of wack (Use a cable tensionmeter)
3) You've got a warped wing (use the digital protractor)
4) Your V-stab / rudder is causing the roll (use a tape measure)
5) You've got asymmetrical flaps (digital protractor)

Geometry is cheap and easy if you're smart enough to know how to apply it.


Regardless - your airplane is not airworthy if it rolls 50 deg/sec without you making it do that.

I would ground your airplane