Why are rotor blades twisted?

• A. to reduce drag
• B. to maintain angle of attack
• C. to increase weight
• D. to simplify manufacturing

Answer: (B)

Rotor blades are twisted so the angle of attack stays roughly the same along the blade as it sweeps through the air. The part near the tip moves much faster than the part near the hub, so for the same blade pitch the tip would experience a larger relative wind and a higher angle of attack. That would make the outer sections lift more, risk stalling, and create an uneven lift distribution and vibrations. By twisting the blade—pitching more toward the root and less toward the tip—the local angle of attack is balanced along the span, giving smooth, efficient lift and stable rotor performance. The other options don’t address the varying airspeed along the blade and the need for consistent lift.