*Incidence satum lines

[Bill TEller]

I am assembling a Global DR llV arf --the instructions say to set
the elevaor @ 0--lower wing @ 0 & top wing @-1/2 seems reasonable. But the wing airfoil is flat bottom with just enough
toward semi symetrical forward to raise the the center of the leading edge about 5/16 or so . the instructions say to set this up with a Robarts meter - problem is the Robarts uses V blocks
on LE &TE & will make the wing flat bottom about 4 or 5 deg neg or so This dos'nt seem rite to me.
Help please,
Bill Teller

[Dave Robelen]

Hello Bill,
You really have two choices. Since the literature calls for the top wing to be .5 deg more negative than the upper, either you choose the lower surface of both wings and use that reference system, or you work with the airfoil reference line between the TE and LE. Is it possible that the way the lower wing fits the fuselage would give you a clue? How about contacting Global? They probably have had this come up already.
Regards, Dave