Empennage Fairing

[rv8or]

I'm in the process of fitting my Empennage Fairing and have a question.
Drawing 43 calls for AN509-8R8 screws to be countersunk into the fiberglass fairing.
The fairing as supplied in the kit is very thin and there does not appear to be enough material to take the machining of the countersink.

What have other people done

Thanks
Rob

 

[RV7 To Go]

I just countersunk the fairing for #6 FH screws. If/when the holes get oversized I will just add a SS tinnerman washer under the screw. I also used fewer screws than indicated. Just 3 along the top of each side of the VS, 1 at the top front, 1 each side at the bottom front and the ones on the lower tab at the back. Holds in place fine. No pic of just the fairing but if you zoom you can just see some of the screws. FWIW.

 

[Carl Froehlich]

And use the same #6 SS Tinnerman washers on your wingtip screws - or anyplace you have a screw in fiberglass.

Carl

 

[RV7 To Go]

Over 8 years and 800 hours on my 7 with the tips, fairings and wheel pants fastened with #6 CS screws and no tinnermans yet. Only 100 hrs on my 8 done the same way. I did forget to mention I use the little plastic washers (Spruce has them) under the screw heads on the tail fairing and pants due to the thinness of the glass and the frequency of removal.

 

[sf3543]

I'm in the process of fitting my Empennage Fairing and have a question.
Drawing 43 calls for AN509-8R8 screws to be countersunk into the fiberglass fairing.
The fairing as supplied in the kit is very thin and there does not appear to be enough material to take the machining of the countersink.

What have other people done

Thanks
Rob

If you create a good fit for your fairing you won’t need so many screws.
I just use regular round head screws on that fairing and it looks fine.
Probably lose about .007 MPH though.

 

[wirejock]

If you create a good fit for your fairing you won’t need so many screws.
I just use regular round head screws on that fairing and it looks fine.
Probably lose about .007 MPH though.

+1
One screw each side fwd. Two aft.
It won't come off without manipulation of the aft ears. The screws just hold it down firmly against the fuse.

Bottom fairing has one each end fwd and aft.

 

[rv8or]

thanks for the replies,

I think I will go with the #6 screws

Rob

 

[DanH]

That fairing is off and on for every inspection. Stiffen it with an added ply or two, scarf in the hook at the HS leading edge, and the screw requirement drops to four.

Fiberglass has low bearing strength. Knife edged countersunk holes are a poor plan in aluminum, and really awful in glass. Use a cylindrical hole and any standard round head, with a nylon washer.