What is used to secure the assembly after drilling the pilot holes?

The correct answer is clecos, which are temporary fasteners used in aerospace assembly to hold parts together after drilling pilot holes. Clecos function effectively during the assembly process, providing a quick and easy way to maintain the correct alignment of components prior to final fastening. They can be inserted into the pilot holes created during the drilling process and are designed to grip the edges of the material securely without causing damage. This allows mechanics to check the fit and make adjustments as necessary before using more permanent fastening methods such as screws or bolts.

Clamps, while useful for securing parts as well, are not specifically designed for use with drilled pilot holes and may not provide the same level of precision alignment. Screws and bolts are used for final fastening but cannot be installed until after the assembly has been correctly aligned and temporarily secured, which is where clecos play an essential role.