I have a friend that is ready to maiden his Senior ARF. He has gone to a lot of work converting it to a tail dragger. I am telling him he needs to open up the bottom of the wind and make the mod that I just put into my Senior. The Senior is one of my favorite planes. Mine has been converted to a tail dragger, has an OS 70 FS, and a glow driver.

My Senior ARF is in it's 5th season. I noticed that the front of the wing was starting to come apart at the joint where the wing rib attaches to the outside rib that joins the wing to the fuselage. I was lucky in that I was given a chance to repair mine.

This is what I did:

I opened up the front third of the wing from the bottom and reinforced the joint. Glue was forced into the area that was coming unglued. I clamped the repair and let the epoxy setup overnight.

The the last rib at the wing root is actually 2 plywood ribs glued together. And that rib has a large oval cut out in it. I presumed to save on weight. But it sacrificed a lot of glue surface to the wood that attaches this rib to the plane body. So I cut and shaped a piece of hard plywood and epoxied it into the oval hole. I had to add and sand a thin piece of bass wood to this plywood to level the surface with the rib. I epoxied and clamped this piece to the outside rib and let it cure overnight. This added a large new properly glued surface.

Then using another piece of hard 3/16 plywood I cut out another rib that fit from the leading edge back to the main strut. It took a lot of time shaping this piece of wood. Once this was done I epoxied this rib to the existing rib and the piece that I glued in previously. Clamped it and allowed it to cure overnight. Then I repaired the blasa planking and covered this area with Monocote.

I used the parts carved on the first wing half as a pattern for the repair parts for the second wing half. So the second half was repaired much quicker.

This repair took me a long time to do. But I do not think the wing will be an issue any longer.

The wing appears rock solid. But I only have 7 flights on it.

As time permits I may go ahead and open up the section of the wing just behind the main strut and see if there are any cut outs in that section of the rib. If so I'll do the same type of reinforcement.

SIG had better get this wing failure issue resolved or no one is going to continue buying this ARF.

If SIG gives you a new Senior I recommend doing this mod. It is time consuming but adds a lot of strength to a known weak area of the wing.

And I am sorry that you lost your Senior.

Todd