Which action is NOT taken during the handling of a mechanical irregularity found by the First Officer?

The action that is not taken during the handling of a mechanical irregularity found by the First Officer is correctly identified as filing a report to operations. Typically, when a mechanical issue is identified, the First Officer's primary responsibilities involve immediate safety measures and operational protocols that directly relate to the aircraft.

Informing maintenance is crucial, as they need to assess the mechanical irregularity to determine whether it affects flight safety and if further action is required. Recording the issue in the eAML (Electronic Aircraft Maintenance Log) is vital for documentation and tracking, ensuring that the mechanical irregularity is accounted for and can be addressed in subsequent maintenance. Reactivating the flight can only occur if the issue is resolved or deemed non-threatening to the aircraft's safe operation based on maintenance feedback.

In contrast, notifying operations about the irregularity is generally not the immediate responsibility of the First Officer. Instead, the focus remains on ensuring the aircraft is in a safe operating condition and reporting to maintenance for thorough checks and actions to rectify the issue.