True or False: The principal use of a band saw in airplane assembly is for trimming and roughly shaping parts.

The principal use of a band saw in airplane assembly is indeed for trimming and roughly shaping parts. Band saws are designed to cut through various materials with a continuous band of metal having teeth along one edge. This tool is especially useful in aerospace manufacturing settings where precise cuts are needed for components that may be too large or awkward for other tools.

When it comes to airplane assembly, the ability of a band saw to make straight or curved cuts allows mechanics to prepare parts to their required sizes and shapes efficiently. This capability is crucial, as many components must be shaped to fit together seamlessly during assembly. The versatility of a band saw makes it a standard tool in the assembly process for both wood and metal materials, depending on specific requirements.

While other options touch on specific uses, the most foundational use is indeed for trimming and roughly shaping parts, which encompasses its primary role in the assembly process without limiting functionality to just cutting metal or fine cuts.