The side that remains elevated dictates the direction of forward push. "The result is that the quadcopter moves in the direction of the side where less lift is created," explains NASA.

Standard propellers are designed to create thrust in one direction only. Every quadcopter uses two clockwise rotation and two counterclockwise rotation propellers.

If the quadcopter started its fall in a normal attitude, all four of the propellers will rotate reverse of its normal direction. The now spinning props will actually act as something of an air ...

By contrast, the HoverAIR X1 Pro mini quadcopter tops out at 16 minutes of flight time. The drone's two propeller arms can be folded in when it's not in use ZeroZero Robotics ...

Parallax's multicore Propeller chip takes off on the ELEV-8 Quadcopter.

The sensors on the little bird are cool and it will move in any direction it needs to avoid a crash be it up, down, left or right. Check out the YouTube video below to see the ArduIMU Quadcopter ...

The Morphy quadcopter shows off its bendy propeller arms View gallery - 3 images Quadcopter drones may be agile but they're also relatively wide and delicate, limiting their potential uses.

Have you ever noticed that military and recreational drones have four propellers, ... "The result is that the quadcopter moves in the direction of the side where less lift is created," explains NASA.