flap interference with rear spar doubler

[alpinelakespilot2000]

Has anyone with a -9 had any trouble with the inboard leading edge of the flap running into the rear wing spar doubler? With my ailerons set to neutral (using the jigs), I cannot get one of my flap trailing edges to align with the aileron without the inboard leading edge running into the doubler. Although I have perfectly straight trailing edges, I've anticipated for a while that that one flap may have up to 1/4" of twist. Van's previously said not to worry about it since 1/4" is not much on 8' of flap, but I don't want my flap and aileron to be that that misaligned.

The only options appear to be:
1. Massage (read slightly dent) the inboard leading edge of the spar so that I get more travel.
2. Somehow straigten the flap... although I'm not sure how given that I've prosealed and riveted the trailing edge.
3. Live with 1/4"+ difference in positions of flap and aileron trailing edges.
4. Build a new flap and HOPE that it comes out better next time.

Any thoughts from 9 builders? Thanks in advance.

 

[Kyle Boatright]

I'm not sure how the -9's flaps are configured, but many of the previous designs had a similar problem. One solution (the one I used) was to cut a slot in the leading edge of the flap slightly outboard of the point of interference. In my case, the slot was an inch or so long. Then, tighten the radius on the flap leading edge so it no longer impacts the doubler.

Hope this helps.

 

[alpinelakespilot2000]

Thanks Kyle. I'm not sure whether I would need a slot or not. I think I'd probably be able to just flatten the l.e. radius a little kind of like you describe in the second step. If by any chance you have a picture in your files somewhere I'd love to see one.

This one flap is frustrating, though, because it's fitting cannot be done in isolation. It is impacted by the wing tips, the ailerons, and the fuselage. It's tough to decide which it should match the most closely knowing that somewhere else it's not going to match no matter what I do!