What are the three common sizes of wire used in safety applications?

The correct answer identifies the three common sizes of wire used in safety applications as .020, .032, and .040. In the context of aviation structural mechanics, wire is frequently utilized for safety applications such as securing components, acting as safety ties, or providing structural reinforcement where mechanical fasteners cannot be used or may not be sufficient.

These specific dimensions correspond to typical sizes used in various applications where strength and reliability are paramount. The .020 and .032 sizes offer a balance between flexibility and strength, making them ideal for safety wire applications that require securing fasteners to prevent them from loosening in operational conditions. The .040 size is often used in heavier-duty scenarios where more tensile strength is necessary.

Understanding these sizes is crucial as they determine the wire's application, and using the correctly sized wire is essential to ensure the safety and integrity of the aircraft structure during operation. The other options either provide dimensions that are not standard for safety wire use or do not reflect the common practices within the industry.