Installed the front tail cone rib backwards on RV-12

[GoN4Broke]

Ok it's confessional time. My first major bone head mistake (that I feel obliged to confess). It happened during the tail cone buildup. I hung all three of the ribs/frames to the J channels on the bottom tail skins clecoed then hung the lower side skins and clecoed. All looked good and so I proceeded to rivet the lower skins together and then the skins to the frames. I then riveted the side skins to the lower skins but did not rivet them yet to the frames - just clecoed. When I flipped over the section to my horror I realized that the frame in the front (the largest one) was in backwards I'm not exactly sure how to get it out of there. I was going to drill out the bottom rivets but the frame will still be hooked into the J-channels of the bottom and side skins (2 on each side). I was thinking maybe I could just disassemble the frame but I'm not sure if that would give me mobility to get it out. Is the slot in the frame that fits into the J channel structurally necessary. I was thinking of bending or even cutting it. Any ideas ?

 

[Bruce Russell]

I would try separating the two frame halves and them maybe you could slide each half forward and off the j channel, then flip each half and reinstall the same way out. DO NOT cut the channel! If separating the halves doesn't work there is no shame in drilling out a bunch of rivets to correct your mistake. Just be careful not to enlarge the holes.
Bruce

 

[rgmwa]

I suggest you contact Vans for advice. I would avoid cutting away the slot, unless they said it was OK.

 

[MartySantic]

Get a few #31 drills, drill out the rivets and remove the skins. Is NOT hard, with the #31 drill you will not enlarge the holes, is just a bit time consuming. But then you will know all is correct.

You may get enough access by removing just a portion of the skin rivets.

 

[videobobk]

Time for the "clicker." That's what the students call the spring-loaded automatic center punch. Drill off the heads, click a couple times on the center mandrel of the rivet, and most times the rivet will pop out. If not, it will drill much easier, without enlarging the hole. First, figure out the fewest rivets you can drill out, then go for it. No big deal--you have wasted some time and rivets, but you have learned a good lesson.

Bob

 

[GoN4Broke]

Thanks everybody for your input. I ended up removing the rivets joining the the top and bottom of the frame so I could split it and try to finess it out. Couldn't quite do it so I called Vans and they suggested I remove about 1/4" of material from the cut out in the frame where it hooks onto the underside of the J-channel. That worked and preserved the flange and rivet hole. I'm pretty sure I wont make that mistake again.