So summing it up.... I'd think these are the probably reasons for tail departure... Too much down thrust, flutter, a balsa root rib, and assembly error by the end user. I think way back at the begining, when they first came out, someone had the stab depart in flight, and they said ace replaced the whole plane due to lack of glue from the factory... If I remember correctly, I think mine had a ply root rib on the stab, and I bought mine in early september.

For those who have changed the down thrust... do you remember what it was stock?