Which rotor configuration uses two main rotors?

Which rotor configuration uses two main rotors?

• A. Direct Shaft Turbine
• B. Dual Rotor
• C. Feathering Axis
• D. Disk Area

Answer: (B)

Understanding rotor configurations helps you see how lift and torque are managed. When a helicopter uses two main rotor assemblies to provide lift, it’s a dual-rotor system. This setup can be arranged fore and aft (tandem) or stacked on the same axis (coaxial), and it’s designed to distribute lift and balance without relying on a single large rotor. The term “dual rotor” directly describes having two main rotors. The other options refer to things other than the number of main rotors: Direct Shaft Turbine is about the engine driving the rotor, Feathering Axis is the axis around which rotor blades pitch, and Disk Area relates to the rotor disk area used in aerodynamic calculations. Therefore, the two-main-rotor configuration is the dual rotor.

Understanding rotor configurations helps you see how lift and torque are managed. When a helicopter uses two main rotor assemblies to provide lift, it’s a dual-rotor system. This setup can be arranged fore and aft (tandem) or stacked on the same axis (coaxial), and it’s designed to distribute lift and balance without relying on a single large rotor. The term “dual rotor” directly describes having two main rotors.

The other options refer to things other than the number of main rotors: Direct Shaft Turbine is about the engine driving the rotor, Feathering Axis is the axis around which rotor blades pitch, and Disk Area relates to the rotor disk area used in aerodynamic calculations. Therefore, the two-main-rotor configuration is the dual rotor.