Heavy Wing -- Discuss

[Smagnuson]

Sorry I didn't reply sooner. I am on the road now but will try and get a pic of something as an example

[johnfurey]

I had a very heavy right wing on my 7. I had to burn about 13 gallons of fuel to balance it out, I weighed 175lbs at the time. I checked all the alignments and usual recommendations. The wing tips were not painted so I tried splitting and moving the trailing edge which had no effect at all so I flew with a large wedge on the underside on the left aileron.

I tried to fix the heavy RIGHT wing by lowering the outboard end of the LEFT aileron by .080 which is what the measurements lead me to believe needed done but that made it worse. So I returned it to where it was.

I removed the RIGHT aileron and milled the brackets to drop the aileron .060 which was slightly more than it needed but not enough to warrant changing. Flys great, looks great! Bottom line is lower the aileron of the heavy wing.

[Airhead]

What is your reference when you say that you have a ?? droop in the right tip? I refer back to the original alignment procedure using the bell crank jig and tooling holes in the tip rib (as shown on Dwg 12A) for setting the aileron tip alignment. This aileron position is then used to mount and position the fiberglas tip. During final assembly, the tip is then typically trusted to align the aileron using the adjustment in the aileron control rod, and the flaps aligned using the aileron for reference. If, as you state, the tip trailing edge is out (again, what reference?) and your aileron/flap configuration was set as I described above (i.e., both ailerons are aligned with the tips) then one or both ailerons would be out of ?design? alignment. It seems this imbalance might easily cause a heavy wing effect.

I found during a double check (measure twice, cut once) of my alignment, before drilling all of the tip mounting holes, that I had not originally managed to correctly align the trailing edge of the aileron with the tooling holes. The problem lay in the way I had set up the reference alignment of the tooling holes. It is, (as you probably remember)) more problematic than the simplistic diagram shown in Van?s drawing because of the necessary stand off of the ?board? as they show it, to clear the skin overhang and aileron bracket. A rethink of my reference mechanism proved that I did not have a good alignment and had to epoxy in the preliminary holes and reposition my tips to realign the trailing edges.

All this may be stating the obvious, but you might start by removing both tips and checking the alignment of the ailerons (and possibly flaps to realign with the ailerons) using the original Van?s prescribed procedure. Then replace the tips and fly. If you had to make any adjustment in the ailerons during this check, you may find that it changed the aerodynamic balance, and that this had more effect than a slightly offset tip. Then you can decide if any adjustment of the tip trailing edge(s) is warranted. At least you will assure yourself that you have the intended aileron/flap alignment and can proceed to troubleshoot from that point.

I currently have 50 hours and have not experienced a heavy wing.

[Smagnuson]

For those interested in seeing an example of the simple fix, drop me an email and I will send pix back. I'm on the road but made some example pix on the aileron of a falcon 2000. I'm a bit challenged when it comes to posting pictures on this sight. Amazing, that I can successfully build an airplane but am stymied by this bit of technology.

Stan.magnuson@gmail

[crabandy]

Pic of Stan's Coffee straw, kinda like a miniature trim tab.

[Steve Melton]

make sure the flaps are aligned to the wing not the fuse. measure from a wing rivet to the trailing edge of the flap. make sure both side are equal.

[Neal@F14]

I "fine tuned" my flaps to correct a heavy left wing on my RV-6. The plane now flies nice and level with ball in center with both my feet on the floor in level cruise and a nice straight line from wingtip thru aileron and flap trailing edge on both sides, but if you level the plane on the ground and use a digital level/protractor device to measure the flaps, they definitely do not measure the same number of degrees when fully retracted or fully extended, still the plane flies perfectly wings level with no rolling tendency with flaps in any position... so I really don't care what degree measurement they ended up with, it's how the plane actually flies that matters. I also lost no top speed doing this either. My RV-6 is remarkably fast for only having a lowly O-320 engine.

[GLPalinkas]

Neal, can you explain "fine tuned"?

[Neal@F14]

Originally Posted by GLPalinkas

Neal, can you explain "fine tuned"?

Adjusted the retracted positions by undoing one of the rod end bearings on the flap pushrod and screwing the bearing in or out a few turns. In my case, I raised the right flap a bit and lowered the left flap a bit. I test flew the plane after each adjustment until it flew level.

[Skysailor]

Vans has a nice two page detailed description of the process the recommend for wing heavy fixes all listed in the order you can follow. It is under the Support tab and FAQ.