What should you calculate first if the distance between each fastener is not indicated on the drawing?

Calculating the total distance between the end fasteners is vital when the drawing does not specify the distance between each fastener. This calculation provides a baseline for understanding the overall layout and spacing required for proper assembly. Knowing the total distance allows for better planning of the placement of each fastener, ensuring that they are evenly distributed along the designated assembly area.

Once the total distance between the end fasteners is determined, it becomes easier to calculate the number of fasteners that can fit in that span and the spacing between them. This step is foundational because accurate placement of fasteners ensures structural integrity and compliance with design standards.

In this context, knowing the total number of fasteners, the size of each fastener, or the space between each fastener comes afterward, as these factors depend on the total distance established first. Understanding this sequence helps maintain precision and efficiency in aerospace assembly practices.