Skin layer issue

[flywithayres]

Hello Brain Trust.

I am about to do the permanent joining of the tail cone and fuselage. The completed empennage kit was a purchase from a previous builder. Today’s task was a step by step review of the tail cone assembly instructions in which I discovered a (hopefully) minor error.
The F-1079 Aft Bottom Skin should be between the F-1078 Forward Bottom Skin and the F-1011 bulkhead. In my tail cone, the skin layers are reversed.
Other than the slight added drag, is there any other issue that would force a re-work? This would mean a drill out of 32 rivets plus some possible ancillary work. Is it a “must do”, a “should do”, or a “not worth the mess up risk”?

 

[PaulvS]

Hello Brain Trust.

I am about to do the permanent joining of the tail cone and fuselage. The completed empennage kit was a purchase from a previous builder. Today’s task was a step by step review of the tail cone assembly instructions in which I discovered a (hopefully) minor error.
The F-1079 Aft Bottom Skin should be between the F-1078 Forward Bottom Skin and the F-1011 bulkhead. In my tail cone, the skin layers are reversed.
Other than the slight added drag, is there any other issue that would force a re-work? This would mean a drill out of 32 rivets plus some possible ancillary work. Is it a “must do”, a “should do”, or a “not worth the mess up risk”?View attachment 73331

Definitely #3, leave it as-is, there's nothing to gain by changing it whereas removal and replacement risks enlarged rivet holes and scrapes etc.
I know of a RV-6A that has the entire F-1079 (equivalent) riveted onto the outside of all the other skins and it has been flying for over 20 years without any issues.

 

[flywithayres]

Thanks for the confirmation. I figured as much but it is always good to have a more experienced opinion. Thanks, Paul.

 

[Dr_Dave_MT]

I’d leave it also. If worried about water intrusion, put a bead of pro-seal at the junction. I’ll bet you’ll never know, or gauge, the minuscule drag change, if any, from the recommended alignment. Still gonna beat the pants off those “other” airplanes.

 

[sblack]

In fact forward facing steps are less draggy than aft facing steps. Aft steps have a small wake. See Hoerner’s Aerodynamic Drag text. Plus one for sealant.

 

[flywithayres]

Good call on the sealant. Thanks.