RV-9A Empennage Fairing

I am working on RV 9 horizontal stabilizer and the plans said to not rivet the skin to the inner ribs in 10 locations for the fairing attach. But nowhere is there a mention if these should be dimpled or not. I went ahead and matched drilled the skin to the inboard ribs.

The plans say to add 632 nut plates on sheet 44.
But do I dimple these 10 holes or leave them undimpled? I am inclined to leave them undimpled since it seems easy enough to dimple after the horizontal stab is together. Does the fairing need these holes dimpled in order to have room for the fairing attach countersink screws?

Thanks

Empennage Fairing

John
I left these un-dimpled. You will note the 632 nut plates won't mate to a dimpled hole. Countersink the Fairing to take the specified screws.
cheers

Leave them undimpled. The fiberglass fairing that sits on top gets dimples machine countersunk into it, and the screws nest into that.

Thanks

Thanks for the replies i am still a little skittish about making a mistake so this feed back is appreciated.

One other consideration is that you probably don't need all of the fastener holes for the fairing. I'm only using a minimal number of screws to secure the fairing. It is very form fitting and it isn't going anywhere!



I ended up dimpling the unneeded holes I left open and put rivets in later.

Installation

When I install a Empennage fairing I just put in 3 nut plates/screws on each surface. Top of horizontal plane is 3 screws.
Side of the vertical 3 screws.
Don't dimple or countersink holes for the screws. You will need to countersink the rivet holes holding the nut plates.

Number 6 screws with Tinnerman washers are fine but I have always used #8 with Tinnerman washers.

Steve, Fairings Etc.