Citabria rigging

[jimnelson]

Can anyone shed some light on a design item? I have reciently leveled my 7GCBC to check my rigging for a heavy right wing. I took some measurements of the wing incidence at various points, and while I was doing so thought I'd check the horizontal stabalizer just for fun. I was surprised to note that it has a negative (leading edge down) angle of 4 degrees. This explanes that while in level flight, at various weights and speeds, my elevator is trimed for nose down, or looking back at my elevator is low in the back. My question is, what is the reason for the negative incidence of the horizontal? It seems to me that this would induce unnecessary drag. Does it have something to do with the airbactic cert?

Thanks for any insight,
Jim Nelson, Superior, WI

 

[citabriaflyr]

I believe all citabrias are like that. My 160hp 7gcaa is like that as well. it always requires nose down trim and in level flight the elevator is down from neutral. I believe it is because the fuselage and tail are from the same jig as the champs, 7ec, 7ac ect... and those airplanes were lower horsepower and required more tail down force in level flight. Jerry M Jr. could probably explain it better than me.

Nathan