Has anyone tried a full-flying V-tail on a 2 Meter Monarch?

From : Don Stackhouse

Toshiro,

I would strongly recommend that you NOT do this! The tail will have stability and control problems, a shortage of control authority, and will require quite a bit of structural re-engineering in the tailboom to properly support the loads. In general, all-flying V-tails have a poor track record. The supposed drag savings is insignificant at best.

In general I am not a fan of all flying tails. It's very difficult to get a good, slop-free structural attachment, and the extra weight at the furthest extremities of the model will weaken pitch and yaw stability and control response. Aerodynamically, an all-flying tail only changes angle of attack during control inputs (unlike a 2-element tail, which also changes camber), so its maximum control authority is weakened. An all-flying tail will need to be enlarged to keep the same maximum control effectiveness as the 2-element surfaces it is supposed to replace.

All-flying tails have their place (primarily on supersonic jets), but in my experience a well-sealed 2-element surface is usually a better investment for model sailplanes.

Don Stackhouse @ DJ Aerotech