Round and Round They Go

Helicopter

• helicopter – a plane that gets its lift from a powered rotor

Helicopter• a large rotating blade can produce enough lift

for flight, just as a fixed-wing airplane can• the blades of a helicopter have the same

shape in cross section as airplane wings• as these blades spin through the air, pressure

differences are created (Bernoulli’s Principle) and air is also pushed downward by the blades

• unlike an airplane, a helicopter can hover in place because they produce their own lift

Helicopter

• as a reaction to the forces produced by the horizontal rotor of the helicopter, the main body of the helicopter spins in the opposite direction as the main rotor

• to provide stability, most helicopters also have a vertical rotor at the back to counterbalance the reaction force of the rotors

Helicopter• helicopters with two rotors have them moving

in opposite directions to prevent the helicopter body from spinning

Autogiro• autogiro – an airplane with a rotating blade

above it