Simplicity and cost. At its most basic form a quadcopter is just two sticks, 4 motors with four speed controllers a flight controller and a battery. [1] if cras

Simplicity and cost. At its most basic form a quadcopter is just two sticks, 4 motors with four speed controllers a flight controller and a battery. [1] if crashed they are easily repaired. a single rotor helicopter on the other had is more mechanically complex, more fragile and more expensive to repair. The reason they became popular was that different technologies (battery, ESCs, flight controllers) all aligned and some very good work was put into open source software to control them lowering the barrier to entry. [1] http://undcon.com/rc/quadcopter/img_20101002_011858.jpg http://undcon.com/rc/quadcopter/img_20101002_011858.jpg