Under what circumstances should torque wrenches be recalibrated?

The correct choice indicates that torque wrenches should be recalibrated at scheduled intervals and also when they have been mistreated. This approach ensures that the torque wrenches maintain their accuracy over time and usage.

Scheduled recalibration is important because torque wrenches can gradually drift from their calibrated settings due to wear and tear, which can occur with regular use. By adhering to a predetermined schedule, users can prevent potential inaccuracies that could impact safety or mechanical performance.

Additionally, mistreatment of the tool—whether through dropping it, over-torquing beyond its capacity, or storing it improperly—can lead to immediate and significant discrepancies in its functioning. Recalibrating after such mistreatment helps ensure that the wrench continues to deliver precise torque measurements, which is critical in aviation maintenance tasks where specifications must be met rigorously.

Overall, both scheduled maintenance and responding to instances of mistreatment help maintain the integrity and reliability of the torque wrench, ensuring it performs accurately when needed.