Page 1 of 1

Inspection holes for wing attach bolts

PostPosted: Sat Jul 31, 2021 6:55 pm
by T41pilot
Just curious what the other B Model builders did for inspection hole locations for the aft side of the main spar wing attach bolts. From what I see, since the seat pan is riveted in, once the bottom skin is attached, there's no way to get at the aft side of the bolts to either remove the wing or just inspect during an annual. Choices for the holes would be bottom skin very near the forward rivet line or a hole in the seat pan and access from the top that way. Just permanently attached my wings and one of the guys helping me pointed that out. Thoughts?

Re: Inspection holes for wing attach bolts

PostPosted: Tue Aug 10, 2021 3:33 pm
by Spaceman
I wondered about this too so I just decided to use the pins that are specified in the plans as an alternate option. I insert the pins from the front so I don't really see much need to access the back side!

Re: Inspection holes for wing attach bolts

PostPosted: Tue Aug 10, 2021 4:39 pm
by T41pilot
Ultimately, I ended up making a 4 inch inspection hole on each side of the bottom skin to access the aft side of my bolts. Best practices call for bolts to be inserted front to back whenever possible so my castle nuts ended up on the aft side. Now I can inspect during an annual or remove the wings if need be(I hope never) and get at both sides of the bolts.

Re: Inspection holes for wing attach bolts

PostPosted: Wed Aug 11, 2021 4:56 am
by Murray Parr
I put mine in the seat pan, couldn't see a way of accessing nuts to install wings without the access panels because I wanted the seat pan completed before taking it to the airport for assembly. Would have posted pictures but they wouldn't download. The passenger side is quite large because I put my ELT under the seat pan ( mainly because I want to keep CG as forward as possible with the Rotax up front)