Which action helps confirm that different fastener types are installed in their correct locations?

The appropriate action to confirm that different fastener types are installed in their correct locations is engineering drawing verification. Engineering drawings provide detailed specifications regarding the types and locations of fasteners required in an assembly. These drawings serve as a blueprint, outlining not only the exact placement of each fastener but also the specifications for the fastener type, size, and quantity.

By cross-referencing the installed fasteners with the information on the engineering drawings, a mechanic can ensure that each fastener complies with the design requirements. This step is crucial for the integrity and safety of the assembly, as the incorrect fastener type in the wrong location can lead to structural failure or operational issues.

Visual inspection and using a fastener gauge may assist in the general assessment of fastener condition and type, but they do not definitively confirm correct placement in accordance with the design intent. Similarly, measuring holes can provide information about dimensions but does not guarantee that the correct fasteners are used in the correct locations according to the engineering requirements. Therefore, engineering drawing verification is the most reliable method for ensuring that fasteners are installed accurately in aerospace assemblies.