How are failed surfaces or systems displayed?

The correct choice is indicative of an important safety protocol used in aviation systems. In aircraft displays, failed surfaces or systems are typically shown in red to indicate an urgent issue that requires immediate attention from the flight crew. The color red is universally understood to signal a malfunction, making it clear that action needs to be taken to address any potential safety concerns. This color coding helps pilots quickly identify critical problems amidst other operational information.

The use of red as the signal for failures is aligned with standard aviation practices, ensuring that any faults or malfunctions are distinctly visible and prioritized during flight operations. By contrast, other colors like green, yellow, and blue represent various levels of operational status or advisory conditions but do not convey the same level of urgency or severity as red does. Green typically indicates normal operation, while yellow can signify caution or an advisory status, and blue may indicate systems that are armed or in a standby state.