Spinning blades push air down. Of course, all forces come in pairs, which means that as the rotor pushes down on the air, the air pushes up on the rotor. This is the basic idea behind lift. Let’s say you want to turn the drone left to right this can be accomplished by changing the power to the four rotors. Two are spinning clockwise and the other two are spinning counter clockwise. By changing their speeds you can turn the drone. To move front back left or right, speeding up two propellers on the opposite side causes the drone to tilt. Now instead of the drone causing a downward force it’s not creating a force on an angle causing the drone to move in the opposite direction.
