Left Flap skins - Note: Check for incorrect roll form at leading edge

I am interested to know if anyone has had an issue with their left flap skin being rolled from the incorrect point. Three of us are building 7's and the leading edge of all three left flap skins have been roll formed with the fold point behind the rivet line. When fitted this results in a severe depression in the skin shape between the ribs because the skin pulls flat across the fold line. Unfortunately we had dimpled all the flap skins prior to realizing the issue so its too late to refold the skins in the correct location. We have compared the skins to the right flap skins and they have definitely been folded in the incorrect location in the manufacturing process (slipped past quality control I guess...?). Once you have dimpled the skins it's too late to refold them without creating a serious mess. We are about to contact Vans to request new skins however before we do I am interested to know how wide spread the problem is.

Has anyone else had this issue? Our kits were all purchased in late 2006.

If you haven't started your flaps I would suggest comparing your right and left skins prior to dimpling. The fold line of the leading edge roll should be just IN FRONT of the rivet line. If the fold line where the roll starts is behind the rivet line it is an issue requiring attention.

Thanks

Thanks for the heads up Jon
I will be checking mine
Jim
7A (STILL on wings)

No probs

No probs Jim.

Some builders may have installed them as is and not noticed if they failed to compare the finished outcome to the right flap. In a nutshell the flatting of the curved section of the skin across the rivet line causes the skin to depress downward significantly aft of the flap spar and in between the ribs. If you put a half decent paint job on your aircraft it will be VERY noticeable and arguably it may me be enough to cause an imbalance of the aerodynamics. If you haven't dimpled the skin it would be a fairly simple exercise to have the straight portion of the skin extended to the other side of the rivet line in a suitable folder. Once dimpled its out of the question. We tried increasing the turnover angle in the top of the flap spar to accommodate the curvature however this results in a significant difference in the clearance gap when installed on the wing (right flap almost flush clearance to top wing skin and left flap approximately 1/4 inch. Not good enough by our standards - we are hoping Vans will replace the skins with a set that have been correctly folded as per the right flap.

It's easy to miss so avoid dimpling without checking the fold point first - will save you a lot of hassle!

My flap skins were incorrectly broke at the trailing edge causing severe distortion when the tip ribs were installed. Vans was great and replaced them.

I had exactly the problem you describe on some replacement flaps I built for my -4. I actually had Vans send me a replacement, only to find it had the same trouble. Their initial response was one of doubt, but I sent them an email with a photo showing a tape measure to indicate the problem. They eventually got me the right skin. My advice is to send em a pic that very clearly shows the problem.

Thanks Sully / Steve -

Figured the problem might be widespread.

Will put the photos together and send them to Vans - no doubt they will probably resolve the issue for us accordingly.

Cheers

I think mine are good

Jon,
Can you post that pic that you sent to Vans?
Mine look like they are bent slightly forward of the rivet line, but would be interested in seeing this. Mine were also ordered in late 2006.
Thank,
Jim 7A Wings

Will do Jim -

Photos are on the camera at the moment and haven't been sent to Vans yet.

About to get that organised - will post them once downloaded.

Cheers

JON

Photos of correct and incorrect fold line on upper flap skins

Jim -

Photos follow as requested.

The file names should be fairly self explanatory in consideration of the posts above.

Regards,

JON

Explanation of images in prior post

Ok - so the images cam through direct without file names so the following should explain more clearly:

First image: Photo of the top flap skin on a friends QB kit - correctly folded in front of the rivet line.

Second image: Photo of the incorrectly folded Left hand side Flap skin with break line behind rivet line

Third image: Photo of a correctly folded Right Hand Side Flap skin

Advise all check your flap skins accordingly.

Regards

JON

Thanks Jon

It appears mine are like number 3.
Thanks for posting.
Jim 7A wings