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Heavy wing

afii58

Member
Phase 1 in rv8....have a heavy right wing...it starts at 157 mph and gets move pronounce as speed increases. Autolilot compensates for it, but hand flying feels like about 2 to 5 lbs of pressure on stick to keep level. Adjusted rt flap up a shade...no joy...leveled flaps again and raise rt aileron up....again no joy. Last thing to try is squeezing left aileron per Van's heavy wing instructions. Question is...the fact that heavy wing dosen't appear until increasing airspeed indicate something else going on that squeezing wouldn't fix....thanks
 
I had the same issue with my -8. Heavy right wing and it was worse with more speed. I would look at your left aileron. I bet it’s sitting just a bit to low causing the left wing to fly up. That was my issue. After measuring both ailerons (on the bottom of the wings) I found the left aileron about .010 lower than the right. Moved it up .010 and now it flys straight hands off.

Here is a good thread. https://vansairforce.net/community/showthread.php?t=189385
 
You said you have a heavy right wing, but then you said you raised the right flap. Wouldn't That be the opposite of the result you want?

Seems like if you think the flaps are out of rig, you should be checking for a right flap thats already too high or a left flap thats too low.
 
I initially had the heavy wing and fixed it with the technique in the manual. It now flies perfect with very light stick forces. My point being, unless you have some other known problem, I'd start with making sure the ailerons are flat before trying other methods.
 
1. ensure your balance spring is neutralized. leave it there until the heavy wing is fixed.
2. quantify the "heaviness" Fill to full fuel, burn off heavy wing until it is perfect. Look at totalizer, that fuel is how heavy the wing is. Many use this and it helps others understand the condition and can relate.

3. Get serious - - read and follow the Vans suggestions on dealing with this. Use #2 as often as needed to avoid variability of "feel" - use a consistent weight and speed for testing.

Last. Slot the hinge and move until better or worse.

YMMV
 
I followed the advise from Vans about fixing my heavy left wing on my RV6:

https://www.vansaircraft.com/faq-technical-builder-items/how-to-diagnose-and-fix-a-heavy-wing/

After everything was confirmed rigged correctly, I measured a slightly high left aileron at the outboard bracket. I removed the bracket (this can be done without removing the aileron from the airplane in about 15 minutes), and filed a slot in the holes that attach the bracket to the aileron. These two slotted holes allowed me to lower my left aileron at the outboard end by 1/6”. This made all the difference I needed on a heavy wing that required full opposite trim (manual) to maintain wings level with balanced fuel tanks. I purchased a new undrilled bracket from Vans and match drilled to the newly located holes in the slotted bracket. A little bit of movement there makes a pretty big difference.
 
Very interesting….have not squeezed the left aileron yet for right heavy wing, so instead took a paint stick and taped it under left aileron inboard trailing edge. Worked great, got a little bit of a left heavy wing starting at 167 mph…so took an inch off of paint stick from outboard edge, now the plane flys great, haha. Still plan on getting rid of paint stick and squeezing aileron……but….why is it that paint stick that adds thickness to aileron works like squeezing the aileron (making aileron thinner)…is it that the paint stick is forcing aileron up causing less lift on that side? And the squeezing is just reducing lift on the aileron?
It does appear left aileron is about 1mm thicker at outboard edge then right aileron
 
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Very interesting….have not squeezed the left aileron yet for right heavy wing, so instead took a paint stick and taped it under left aileron inboard trailing edge. Worked great, got a little bit of a left heavy wing starting at 167 mph…so took an inch off of paint stick from outboard edge, now the plane flys great, haha. Still plan on getting rid of paint stick and squeezing aileron……but….why is it that paint stick that adds thickness to aileron works like squeezing the aileron (making aileron thinner)…is it that the paint stick is forcing aileron up causing less lift on that side? And the squeezing is just reducing lift on the aileron?
It does appear left aileron is about 1mm thicker at outboard edge then right aileron

What you've done is create a gurney flap. in this case, it's basically acting like a fixed trim tab on your aileron.
 
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