7 left elevator trim spar

[T.S.]

Vans states to dimple the bottom and machine coutersink the top of E-606PP trim spar.
a)Has anyone dimpled the top last 4 holes tward the tip? The hinge ends prior to these.
b) Would there be a visual difference between the countersunk and dimpled rivets in the row?
Thanks,
T.S.
7A elevators

 

[robertahegy]

The purpose of the countersinking is so the hinge will lay flat on the bottom of the upper spar flange. Since the hinge doesn't lay beneath the spar at the last four holes, it should not matter. I would still countersink them just to avoid any chance of discontinuity possibly caused by the dimpling process. When countersinking, clecoe the hinge in place and use it as an extra guide for the pilot on the countersink. This will keep the hole better aligned, allow you to match the countersink to the hinge (if you should go below the flange), and prevent the hole from getting too big. Use some scrap to help countersink the holes where the hinge does not reach the 4 holes.

Happy Building!

Roberta