What does a Red X indicate when reviewing aircraft forms?

A Red X indication on aircraft forms signifies that the aircraft is unsafe or unserviceable. This specific marking is used in aviation maintenance to clearly denote that there are issues that must be addressed before the aircraft can be considered airworthy. When a Red X is present, it alerts maintenance personnel and flight crews that the aircraft requires urgent attention and cannot be flown until the identified discrepancies are resolved.

This system of marking is crucial for maintaining safety in aviation operations, as it helps ensure that any aircraft that may pose a risk does not enter service until thoroughly checked and cleared for safe operation. The clarity of this marking helps build a standardized method for tracking the safety status of aircraft across different operations and maintenance scenarios.