Where did you guys put screws in the aft end of the empennage fairings?

[Desert Rat]

I've been looking online for the last hour and while I see tons of beauty shots of finished empennage fairings, there aren't many of the screw layout under the elevators aft of the inspection cover.

The print for the RV7 has you drill out a longeron rivet that's common to the fwd flange of the aft double bulkhead. But there's a bolt and nut right behind that rivet, so there's not much room in there, plus, it would be nice to get that fastener a little further aft so that I don't have so much fiberglass aft of there just flopping around.

I found a picture from about ten years ago on somebody's build log where they put a screw in much further aft, but I didn't wade through the entire log to see if it worked for them. It looks to me like the rudder might hit it. My question is; has anybody gone that route and is there room back there for a nut plate and screw without the rudder hitting it?

I've attached a couple of pictures to make this a bit more clear. The photo is the one I found online, the print is from the RV7 manual and I've marked the plans location in red and the proposed location in blue.

I suppose I can hang the rudder back on tomorrow and figure this out, but it would be nice if somebody could save me the effort...

 

[Stevea]

This is an after market fairing on a -6, but the screws should be in about the same place. The last screw goes on with a nut, instead of into a nut plate because I couldn't fit a nut plate (even a mini one). You can just see the nut on the far side screw. The nut clears the rudder leading edge throughout the rudder range of motion. I didn't like the idea of the fairing back corner being able to move around either.

 

[PaulvS]

This is how I did it on a -6A, which is sort of similar to -7. It was tight to get the two #8 plate nuts to miss rivets and one of them is single lug. The third aft screw is an afterthought because it looked like it needed more support there. It is a #6 screw tapped into the longeron. The exact location should be checked with the VS on to ensure there is no interference with the spar flange and it may need a short screw to achieve that.

 

[StephenC]

My -6 had screws with nuts in the last two holes which were an absolute pain to remove due to the wrench needing to be held in place while you removed the screws. I did the same as Paulvs and threaded the holes up to #8 screws which turned out to be a great idea. I did find the last hole needed a very short screw to ensure clearance but all worked out ok.

 

[RV7A Flyer]

I did find the last hole needed a very short screw to ensure clearance but all worked out ok.

+1 on my 7A, to ensure clearance from the rudder when fully operated side-to-side.

 

[robertahegy]

Screws went into the holes where clecoes are inserted.

 

[RV6_flyer]

On my RV-6, I did not want a lot of screws and a large opening for the elevator horns. 4 screws are all that hold the fiberglass to the airplane. The fairing is a one of a kind made in place on the airplane. I used scrap sheet metal to close the aft bottom end out like Dennis Ashby did on his RV-6 before mine flew.

 

[uk_figs]

Tapped the longeron and used short screw, seems fine and am careful to not overtighten, I do use stainless tinnerman washers and screws throughout my plane when attaching fiberglass parts
Figs

 

[Draker]

I tapped my longeron to #6 and used a very short screw so it did not interfere with the nut behind it. One of them is already stripped so I had to upsize to #8.

 

[Webb]

I’m stealing what Mike Foss did on Man O War. I managed to freeze the YouTube video at the right time.

He cut off part of the top fiberglass piece and made an an extended inspection plate. You can see a detailed account of what he did. Look up RV-8 Tail Mods.