Do you think your planes would perform as well with a cruciform tail as opposed to a V-tail? I respect your opinion and understand the weight benefit, but is there any other benefit?

From : Don Stackhouse

No, I would not expect them to perform as well. The individual surfaces would be smaller (you're dividing up approximately the same total area over a larger number of surfaces, so the individual surfaces get smaller). This reduces either their span and/or their Reynolds numbers, both of which hurt their aerodynamic efficiency. At HLG and 2-meter tail Reynolds numbers this can be very significant. In addition, a cruciform tail has more corners, and therefore more interference drag.

The differences are small, and a typical sport flyer would probably have trouble measuring them. The straight-tail option for the older Monarchs and Wizards (all versions prior to the new fuselage with the closed tail saddle we introduced last fall) had "X" tails like the Maple Leaf's (years before the Maple Leaf folks coined the term). It was a conventional tail with a skeg to keep the stab out of the weeds on landing, aerodynamically nearly equivalent to a cruciform tail. The handling was equivalent to the V-tail version, and performance was almost the same, if you allow for the weight increase (a serious aerodynamic issue itself, on any span-limited class).

However, for smaller models, the overall aerodynamic benefits, in addition to the structural benefits, fall in favor of the V-tail. If or when there is a net benefit to some other type of tail, we will use it.

Don Stackhouse
DJ Aerotech