Holes don't match

[rwarre]

Began riveting the leading edge to the left main spar. Discovered that two holes on the outside of the rib flanges do not match the spar holes. They are about 1/2 inch off. Specifically the two problem ribs are the 4th and 5th starting at the outboard rib. I checked the right main spar and found the same problem. I have checked all the ribs for identification and measured the hole distances. The main spar holes for these two ribs in question are not equidistantly spaced. Anyone run in to this or did I miss something. Vans said to just back drill and move on.

 

[rzbill]

Dim Memory

Study the plans and assembly instructions carefully. Although it has been over 2 years since I worked on wing ribs, I do remember a notation somewhere in the provided documentation about the hole mismatch on 2 ribs. As Vans said, drill and go.

 

[pgroell]

Read the manual

It's written in the manual, some holes won't match.
You have to use the spar as a template to backdrill the ribs; and not the other way round.
Ask me how I know.
Problem HERE
Answer HERE
Built on.

 

[n615ks]

Missing Holes

It's also been some time for me, as I am a sloooow builder and had to take a year off during early fuse construction. The reference to the missing holes is in the manual, page 7-3 Assembling the Wing Skeleton, 2nd paragraph.

A word to the wise.....read the manual once through before doing anything, then use it as a checklist while building. These holes would normally be drilled during the drill-deburr-prime process, not during actual riveting process.