How do helicopters fly?
A helicopter has two rotors, the main rotor on top and another rotor on its tail. The rotors are made in the shape of airfoils. When the helicopter’s engine turns the main rotors at high speed counterclockwise (looking from above), the pressure on the bottom side of the rotor is greater than the pressure on the top, making the helicopter lift off straight up into the air. However, even though they share the same basic way of getting off the ground, helicopters are much more complicated than airplanes. Planes can go forward, up and down, and left and right. Helicopters can do the same, while adding the ability to go straight up, backwards, or just hover in midair. The key to these extra abilities is that the helicopter pilot can change the angle of the rotor blades. The steeper the angle of the blades, the greater the amount of lift, and the faster the helicopter rises. To go forward or backward, right or left, the pilot tilts the blades in the direction he wants to move. The need for a
