R/C helicopters, what makes the 3D?

Question

In radio control Helicopters, what makes a heli fly 3D?

Answer 1

3D is usually defined as a combination of 2 or more moves. This usually involves the heli flying upside down, flipping, and/or pirouetting. This is accomplished by a heading hold gyro, usually computer radios, and most importantly, pilot skill.

Answer 2

jim m is right about the radio system needing a gyro and a heli computer radio (Like the 6EXH). But, in most flying models, 3D also means you need a powerful motor (with a very responsive ESC in electrics), and digital servos.