What should you check if you see a red X on an airspeed indicator?

Seeing a red X on an airspeed indicator is a critical issue that indicates a malfunction or failure in the airspeed measurement system. This red X usually signifies that the instrument is not providing valid airspeed data, possibly due to electrical issues or a failure in the sensor system.

Resetting the circuit breaker is an appropriate initial action in this scenario. Circuit breakers serve as protective devices for electrical circuits, and a tripped breaker can interrupt power to the instrument. In many cases, simply resetting the breaker can restore power to the system and resolve the issue with the airspeed indicator.

While other options could be relevant in certain contexts—like performing a system diagnostic, inspecting wiring connections, or replacing the indicator—resetting the circuit breaker is a practical first step when faced with an immediate failure indicated by a red X. It addresses a common issue that could restore functionality without needing further more complicated procedures or replacements. When troubleshooting aircraft systems, starting with simple solutions before moving to more complex ones is an effective strategy.