Which feature directs airflow into the engines on the blade assembly?

• A. A blade fairing made of plastic foam covered with reinforced nylon rubber
• B. An aerodynamic winglet
• C. A carbon fiber tip cap
• D. A metal horn balance

Answer: (A)

Understanding how airflow is directed into the engine through features on the blade assembly is the key idea. The blade fairing made from plastic foam and covered with reinforced nylon rubber acts as a streamlined cover around the blade root, shaping the flow as it exits the hub and enters the engine intake. This shaping helps keep the airflow attached and directed along the intended path, reducing disturbances and ensuring the engine receives a steady supply of air at various blade speeds and attitudes.

The other features serve different purposes: a winglet improves wing efficiency by managing tip vortices on a wing, not on a blade assembly; a carbon fiber tip cap is about reducing tip mass and preventing flutter, not steering airflow into the engine; a metal horn balance provides mass balancing to reduce flutter, not airflow direction.