FOR ME 3D IS ALL THE MOVEMENTS YOU CAN DO WITH A PLANE ON THE UP LIST OR NOT,,,,, YOU CAN DESCOVER NEW MOVES,,,, ON FOAM SOMEBODY CAN FLY ON REVERSE, NOW ON THE FLYING CIRCUS ARE SHOWING A 4 STROKE ENGINE WITH "PASO VARIABLE" MOVE PITCH, OR REVERSE....

TO DO THAT YOU NEED A LOT OF POWER ON A VERY VERY LIGHT PLANE.....

SERGIO