What happens if an aircraft is marked with a Red X?

A Red X marking on an aircraft indicates a status of "unserviceable" and signifies that the aircraft has a significant issue that must be addressed before it can be considered safe for flight. This designation alerts maintenance personnel and flight crews that the aircraft cannot be operated until repairs or inspections confirm that it is once again serviceable. The safety of the aircraft and those on board is paramount, and therefore, it cannot be flown until deemed fit for operation after the necessary maintenance actions have been completed.

The other options do not accurately reflect the implications of a Red X marking. For instance, the idea of flying the aircraft with restrictions instead of requiring repairs contradicts the serious nature of the Red X status. Additionally, suspending inspection requirements goes against established safety protocols, as maintenance checks are crucial in identifying and rectifying issues before flight. Lastly, stating no action is needed fails to acknowledge the critical condition indicated by the Red X, emphasizing the importance of immediate maintenance intervention.