Who can perform the repair of aluminum propeller blades?

The correct choice indicates that the holder of a powerplant rating is authorized to perform repairs on aluminum propeller blades. This is due to the specific skills and knowledge associated with powerplant ratings, which cover propulsion systems and their components, including propellers.

A powerplant mechanic is trained to handle various aspects of aircraft engines and related systems. This training encompasses understanding the materials used, repair procedures, and safety protocols, making them well-equipped to repair aluminum propeller blades, which fall under their area of expertise.

The other options do not possess the specialized knowledge required for this specific task. While a certified mechanic has a general understanding of aircraft maintenance, this does not imply the expertise needed for specific repairs like those required for aluminum propellers. Similarly, an airframe rating focuses on different systems, and designated repair stations usually handle more extensive repairs and overhauls rather than being exclusive monitors of repairs. Therefore, the powerplant rating is crucial for ensuring the correct and safe repair of aluminum propeller blades.