What is the responsibility of the trail element in a squad column fire team when crossing an LDA?

In a squad column fire team transitioning across a Linear Danger Area (LDA), the trail element's primary responsibility is to establish near side security. This is crucial because as the team crosses the LDA, the first element is vulnerable while moving through the open space. The trail element positions itself to cover the team's rear and ensure that the area immediately adjacent to the LDA on the near side is secure.

By focusing on near side security, the trail element can effectively prevent any threats from approaching the team while they are in a potentially exposed position. This role is vital in keeping the entire unit safe and allowing it to successfully complete the crossing without being ambushed or attacked from the vulnerable side.

While setting up rear security, leading a change in formation, or coordinating with the front element are also important tasks in different contexts, they are not the primary focus of the trail element during this particular maneuver. The trail element's responsibility to establish a secure position near the LDA allows for better overall squad safety and operational effectiveness.