Helicopter rotor Facts for Kids

Helicopter rotors

A rotor is a spinning part of a helicopter that helps it fly. It creates the force called lift, which pushes the helicopter up into the air. Main rotors lift the helicopter vertically, while tail rotors help control its direction by pushing it horizontally.

How Do Helicopter Rotors Work?
- Main Rotors and Tail Rotors
History of Rotor Development
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How Do Helicopter Rotors Work?

Helicopter rotors are like giant spinning wings. They have long, flat blades that are shaped to push air downwards. When the blades spin very fast, they create a difference in air pressure above and below them. The lower pressure above the blades and higher pressure below them create an upward force called lift. This lift is what makes the helicopter rise off the ground and stay in the air.

The pilot can change the angle of the rotor blades. Changing this angle allows the helicopter to go up, down, or move forward, backward, or sideways.

Main Rotors and Tail Rotors

Most helicopters have two main types of rotors:

Main Rotor: This is the large rotor on top of the helicopter. It provides most of the lift to get the helicopter into the air. It also helps move the helicopter in different directions.
Tail Rotor: This smaller rotor is usually found on the tail of the helicopter. Its main job is to stop the helicopter from spinning around. When the main rotor spins, it creates a twisting force on the helicopter's body. The tail rotor pushes in the opposite direction, keeping the helicopter stable and allowing it to turn left or right.

Some helicopters, like the Kamov Ka-50, use two main rotors that spin in opposite directions instead of a tail rotor. This design is called "coaxial rotors." Other helicopters might use a special fan inside the tail, called a Fenestron, or a system called NOTAR (NO TAil Rotor) to control the spin.

History of Rotor Development

The idea of spinning blades for flight has been around for centuries. However, modern helicopter rotors really started to take shape in the early 20th century.

Before powered helicopters became common in the mid-1900s, a clever inventor named Juan de la Cierva did a lot of important research. Cierva was from Spain and worked on machines called autogyros. These aircraft used an unpowered rotor to create lift as they moved forward.

Cierva is famous for successfully developing rotor systems with multiple blades that could move freely. This design, known as a "fully articulated rotor system," allowed each blade to flap up and down and change its angle independently. This made rotors much more stable and controllable. His work was very important for making helicopters safe and able to fly well, and his ideas are still used in many modern helicopters today.