Helicopters often used to feature 2 main rotor blades, but over time, that number has grown significantly, with some helicopters sporting up to 8 blades. Typically, as a helicopter increases in size, it weighs more, meaning it requires more lift to remain aloft. Using additional blades allows designers to increase the entire rotor system surface area while keeping the size of each rotor blade as small as possible. Read on to learn why some helicopters only have two main rotor blades, while others have many more.