Learning Objective 021.02.02.01.02: State the advantages and disadvantages of composite materials compared with metal alloys by considering the following: strength-to-weight ratio; capability to tailor the strength to the direction of the load; stiffness; electrical conductivity (lightning); resistance to fatigue and corrosion; resistance to cost; discovering damage during a pre-flight inspection.

The appropriate action to take if an operator notices corrosion on metal parts of their aircraft fleet is to repair, prime, and paint the damaged parts. This is important because corrosion can weaken the metal and compromise the structural integrity of the aircraft, which can be a safety hazard.

Replacing the metal parts with plastic or composite materials may be an option, but it can be expensive and may not always be feasible. It is also important to note that different materials have different properties, and they may not be suitable for all applications.

Washing the aircraft thoroughly after each flight may be important for general maintenance but may not prevent corrosion. A notable point is that washing the aircraft after every flight could cause some water based corrosion or rusting over time, so is not a good idea to fight corrosion.

Painting over the corrosion to protect the area and add strength is not a recommended practice as it does not address the underlying corrosion issue and can lead to further damage.

Therefore, the best course of action is to have the affected parts assessed by a qualified technician and have the corrosion removed and repaired, and then properly primed and painted to protect against further corrosion.