Match drilling side firewall flanges

[Michael Burbidge]

I'm to the point of match drilling the side firewall flanges as shown on Page 29-08. On one side the skin holes line up perfectly with the holes in the firewall flanges. On the other side, they are about 1/3 hole off. (without clecoes) I think by starting at the bottom and installing clecoes all the way up I can get them to line up.

Did you find the holes line up perfectly (without clecoes) on both sides, or did you have to "man-handle" to get things to line up. Perhaps this is why we match drill at this point.

Michael-

 

[Marc Bourget]

You haven't cleeco'd up the whole firewall?
Is the overall fit OK, matching curves, etc., at least from spot to spot.

First thing I'd try is cleecoing the whole firewall from different starting points. (Top, bottom, one side to the other). Are they drilled #30? If they're 1/8", use a rivet from time to time as a locator. Cleecos aren't adequate for location.

You might get it to "lay in place" with a little strategy.

If not, consider taking photos and reporting back.

 

[Michael Burbidge]

I removed the blue plastic from the inside of the skin and started over. By clecoing from the bottom of the flange and moving up I was able to get a good fit. It’s still tight but I was able to get every cleco in.

At this point I believe the holes on the firewall flange are undersized so I can’t use rivets to check alignment.

 

[mc607]

Page 29-08 step 12 Dimple the corresponding holes in the SS firewall flanges.