Which type of wing is characterized by having two or more blades that generate lift?

• A. Fixed wing
• B. Controlled wing
• C. Rotary wing
• D. Flexible wing

Answer: (C)

The type of wing characterized by having two or more blades that generate lift is known as a rotary wing. This design is exemplified in helicopters and rotorcraft, where the blades rotate around a central hub, effectively creating lift through the rotation. The lift is generated by the airfoil shape of the blades as they move through the air, much like how an airplane wing generates lift, but with the crucial difference being the rotary motion.

In contrast, fixed wings maintain a stationary position relative to the aircraft body and generate lift through their shape and angle relative to airflow, typical in conventional airplanes. Controlled wings do not refer to a distinct type of wing structure but rather imply elements of flight control, while flexible wings may refer to wings designed to change shape or adjust to different flying conditions but do not inherently denote any specific lift-generating mechanism like the rotating blades of a rotary wing.

Therefore, understanding the mechanics of rotary wings clarifies how they create lift by utilizing the continuous movement of blades in a circular motion, setting them apart from non-rotary designs.