Rudder trailing edge drilling

[Lemmingman]

During my EAA class the instructor had us drill the trailing edge holes on about an 84-degree angle. As I'm progressing through the instructions this advice is conspicuously absent. I've checked all through the instructions and there is plenty of advise about setting the rivets, etc...but nothing about drilling the holes at 84 degrees.

Is this process a hold over from a previous age when pre-drilled kits were not available? Is it still a good idea to do it? If so...84-degree with reference to what? I assume the rudder skin.

Thanks again.

 

[randyintejas]

I drilled mine stright up and down and it worked great.

 

[mcencula]

Probably doesn't matter

I'm guessing the instructor was splitting the angle between the left and right side skins. However, a #40 bit will make a loose enough fit with an AN426AD3 rivet that even if you drill exactly perpendicular, the rivet heads will just smoosh into the dimples regardless.

 

[Low & Slow]

Drilling Trailing Edge

No wish to be pedantic, but the instructions for drilling the trailing edge require one to drill the hole perpendicular to the chord line. If the hole is perpendicular to the chord line, it will be at approximately an 84 degree angle to the control surface because the angle between the chord line and the surface is about 6 degrees.

 

[flion]

I agree with James; that's the way it was in my RV-10 plans. I'm not where I can put my hands on my RV-7 preview plans so I can't say if it's a plans failing or not. That said, six degrees over such a short difference probably does not matter that much.