Mounting the V-Tail is what I hate to do. It seem like there is too much cuss and cry during the cut and try. However, a couple of measurements and a bit of trig with a simple procedure makes this nearly as easy as mounting a conventional tail. OK, nothing is that easy, but then the lower drag and redundant elevator function makes it worthwhile. The drag is lower because there is one less junction between the fuselage and flight surfaces.

First, measure the width of the fuselage where the Leading Edge and Trailing Edge of the V-tail meets the fuselage. Subtract the TE width from the LE width and divide by two. I try to measure this to a 1/32" accuracy, though my eyes are starting to water (CA fumes). Take the Tangent of the angle to horizontal (180 – {V-tail angle})/2, for a 120 degree tail, it’s 30 degrees. So working out the trailing edge position is : [(LE width– TE width)/2] x tan 30. This distance is the amount that the TE of the V-Tail is lower on the side of the fuselage than the LE for zero incidence.

Place the fuselage with the wing mounted so that the leading and trailing edges are blocked up an equal amount (zero-zero) on the obligatory flat surface. Mark the position of the leading and trailing edge of the tail on both sides of the fuselage, making sure that the trailing edge is marked lower than the leading edge on the side of the fuselage by the amount that was calculated. Remove the wing. Make a template of the V-tail’s airfoil cross-section and mark both sides of the fuselage with the bottom of the airfoil. Turn the fuselage at the same angle that the tail is to be mounted and block up so that you can cut into the tail at the correct angle by just making a vertical cut. Turn and repeat. If you are always going to use the same angle, just make a plate that mounts to the firewall that holds the fuselage steady at a 30 degree angle.

Bob