Avid Mk4 aerobat - wing replacement question

[pwags 0]

I'm looking for advice on the position of the flaperon control arm in the turtledeck bearing. I acquired a new to me aircraft that had a damaged wing and a used replacement wing. After hanging the replacement wing I notice that the flaperon control arm sits about 1 inch higher on the turtledeck bearing than the original wing.

1. Is this an issue?
2. Does this misalignment indicate other problems with the replacement wing?
3. Can I just modify the bearing attachment positions on the fuselage and turtledeck appox. 1 inch higher to accommodate the control arm height? 

Thanks for reading my post and for giving any advice that you have to offer.

Paul from north MO

 

[wypaul 448]

Rib tails attached behind the tank are probably not placed proper/not he same are the existing wing.  If both were the same it would be workable but probably not so much the way it stands.  You should be able to correct them to match the other wing without to many issues. IMO

[1avidflyer 1983]

Hi Paul,  welcome to the group.  I would ask a few questions before I wanted to give an answer or express my opinion.  When the wing was damaged, was any damage done to the  wing attachment points on the fuselage?  Does it look like the flaperon hinge mounting position on the ribs is the same from one wing to the other?  I'm wondering why it's different, before looking for a fix.  JImChuk

[HKSMark4 4]

The Wing extensions attached to the Fuel Tank are probably installed at too high an angle.  If they are attached with structural adhesive you can soften and remove them using heat.  Compare the distance between the bottom of the wing and the flaperon with the left wing dimension.  Put a string line between the outer flaperon hanger and the nylon bearing,  I'd lthen oosen the bottom bolt and remove the top bolt on all of the flaperon hangers.  Adjust the hangers so that the flaperon now sits on the hanger.  You should be able to figure out if the Wing Trailing edge extensions need to be relocated.  I had a similar problem with an Avid I just reconstructed.  Fortunately it was only the inner extension that was out of wack. Take a look at my rebuild video.  You can see the problemand fix near the end.  youtu.be/2qsTK7rQRbI    Let me know how you make out.  Ed

[pwags 0]

Thank you for your responses, Paul, Jim and Ed.

Here's some more info.

Thanks, Ed for the video link. I'll check that out.

The damage to the original wing was a deep groove worn in the front spar directly in front of the gas cap. I was told that the damage occurred during transport while the wing was off. It looks like it was also ground looped after the spar damage, because the wing tip and last flaperon bracket are broken off. I think that I could put an internal liner inside to patch it, but I am trying to use the replacement wing since I have it.

 

The carry thru tubes appear to be undamaged and attachment points measure the same as the other side.

The hinge mounting holes in the rib tails are not the same (see pic), and at first, I planned on correcting that only, but to get the flaperon control arm in the correct position the hinge mount must sit too far down on the rib tail to have good hole edge clearance. 

Replacement wing holes are slightly forward from the hanger tail and rotated down a little. The flaperon hinge would have to be in this position to fit the nylon bearing. 

Here is a pic of the good, left side wing hanger. The alignment is much better.

 

All opinions are much appreciated. 

Thanks, Paul

 

 

[1avidflyer 1983]

Looks like the biggest difference is how the hinges were bolted to the rib tails on the new wing are so much further from where they are on the other wing.  Perhaps fill the old holes with epoxy and drill new ones?  Maybe replace the bearing or raise it up just a bit to get the hinge onto the rib like the other side is.  Maybe even .025" plates on the sides of the rib tail with 3 holes in them.  (perhaps even spread the hinges a bit to fit over the plates after they are epoxied to the rib tail.) Two holes match the existing holes in the hinges and one further forward.  Just my 2 cents worth and worth what you paid for it.  :-)  

[saskavid 47]

One thing to keep in mind as well when and if you are going to redo the holes for positioning the flaperons is the angle between the flap bracket and the top of the wing is at the trailing edge is supposed to be 54 degrees for a speed wing, manual specified and for the inboard and outboard brackets is labeled critical.