What symbol is used on aircraft forms for equipment that has gone overdue?

The red dash (-) symbolizes equipment that has gone overdue on aircraft forms. This visual cue is critical for maintaining safety and operational readiness, as it alerts maintenance personnel and aircrew to the status of the equipment. An overdue indication typically means that the equipment has not been inspected, serviced, or replaced within the required timeline, which could pose risks during flight operations.

The use of a red dash is standard across various operational documents to create a uniform understanding of overdue status, prompting immediate attention to address the issue. The other symbols have different meanings; for instance, the blue circle often indicates items that are on hold or waiting for action, while a yellow triangle usually signifies caution or items that need monitoring. The green check represents equipment that is in good condition and has passed inspections. This color-coding system is essential for quick visual identification and enhanced communication in aviation maintenance contexts.