JENSWAY

JENSWAY

Member
Hi all!

I've recently attended an air show and noticed that on most of the RVs, their leading edges have dents where the rib webs have pressed against the skin.
I noticed on my dad's C170B, the ribs are cut off at the leading edge (i.e. the last pre drilled hole on a RV leading edge rib...)- no dents.

I have read through most posts about L.E. denting.

Please would someone help and confirm if my idea of slightly bending the last few fingers on the rib web ( the ones at the L.E. that aren't pre drilled) past 90 degrees. In this way, they don't physically touch the leading edge.

By doing this, I found that fitting them in the jig hasn't been an issue
.
IMG_1912_zps1dec8061.jpg.html
 
That may work for install, but it seems that when you go to rivet, you will have a gap between materials, which would make it impossible to properly set the rivet, which could lead to trouble down the road. I haven't noted any real dents on my leading edge; I can see a slight bit in the reflection, but if I run my hand along it, it's barely noticeable. After dimpling the fit of everything will loosen up, and the ribs will slide in more easily.
 
The offending area is the edges of the tabs. You can see it in the image link posted by the OP.

Aerhed is right that some advice has been given to grind these tab edges to better smooth the rib profile and make it fit the skin nose better. I did not..and I have bumps that I notice now (I did not then).
 
Ditto on the grinding recommendation. Works great and is quick to do to each rib. Just run the leading edge of the rib flanges on the scotchbrite wheel until you get a nice continuous smooth curve.
 
I remember beveling the flange tabs with the scotchbrite wheel to knock off the hard edge. Like someone mentioned above, I too can clearly see the reflection on the leading edge at each rib that makes it look like there is deformation, but when I look down the length of the leading edge from one end or the other, there is no indication of deformation at the ribs. I looks and feels smooth all the way. I suppose it would not take much "deformation" to cause light to reflect and appear excessive.
 
Really bad fit

I had A LOT of trouble with fitting my leading edge ribs. When I forced them into place you could see each nose rib under the leading edge skin as if it was a fabric covered wing! I tried everyone's suggestions about grinding the front tabs etc, but it was not nearly enough. Vans said I would have to lightly hammer the ribs to re-profile. I've talked to other builders who have had the same issue. The illustration below is slightly exaggerated, but not much. The dashed line shows the new profile I had to reshape each rib to:



You really want an easy fit, especially with the fuel tank nose ribs as you don't want to be struggling with them with proseal flying everywhere.
 
Thanks all for the advice. I contacted Vans and they recon that bending the flanges is ok. I have subsequently fitted the leading edge assembly to the wings and the tank/ outboard sections join together without any noticeable bulging or deformation. Avi8tor Tom has hit the nail on the head-:cool:
 
You must log in or register to reply here.