Which of the following refers to a form of fire control where the weapon is swung across an arc to engage targets?

Swinging traverse is the correct term that describes a method of fire control where a weapon is maneuvered across an arc to effectively engage multiple targets. This technique is essential in combat scenarios where threats may be positioned along a broad front or in varying locations, allowing the operator to efficiently bring fire onto these targets without needing to reposition the weapon significantly.

In contrast, the other options refer to different concepts. 'Search' typically pertains to the methodical scanning of an area to locate targets rather than the act of directing fire. The 'tiered approach' often refers to a strategy involving multiple levels or layers of action or command, not specifically about engaging targets with fire. 'Stationary aim' implies holding a weapon in a fixed position to fire at a static target, lacking the dynamic movement inherent in a swinging traverse.

Thus, the swinging traverse is key for adapting to rapidly changing battlefield conditions, making it a vital skill for soldiers to master in order to maintain effective fire control in various engagements.