why is this thing stable in roll? it flies, and with enough control to fly circuits around the yard, I bet a roll or loop is not out of the question.

[link=http://www.rcuniverse.com/forum/m_8222254/tm.htm]http://www.rcuniverse.com/forum/m_8222254/tm.htm[/link]

I am completely baffled, my only guess is the chines have some dihedral effect. but the center of mass is way above the center of lift (the sled)..