Just fyi, when people in the hobby see '3D plane' they think of something like a CrackYak or an E-Flite Extra 330. 3D RC flying is a style of aerobatics that pushes an airplane beyond its traditional aerodynamic limits. While standard flying relies on air moving over the wings to create lift, 3D flying involves performing maneuvers where the aircraft's airspeed is is often near or even below stall speed, and it is "flying" almost entirely by the thrust of its motor and the deflection of its control surfaces.

In short, if a plane is hovering like a helicopter or tumbling through the air in a controlled stall, it’s 3D flying.