Which hand should you use to hold the drill guide firmly against the assembly surface?

Using the non-dominant hand to hold the drill guide firmly against the assembly surface is optimal for stability and precision during drilling operations. The non-dominant hand typically provides a steady support base, allowing the dominant hand to focus on maneuvering the drill. This strategy ensures that the drill guide remains correctly aligned, reducing the risk of misalignment or slipping, which can lead to errors in the drilling process.

This method is particularly important in aerospace assembly, where accuracy and adherence to specifications are critical. By securing the drill guide with the non-dominant hand, you maintain greater control over the drilling action, making it easier to achieve the desired results without compromising the integrity of the assembly.