Once the ECU determines that the intercepted signal matches pre-programmed data, what is transmitted to the aircrew interfaces?

The choice of "alert" is particularly fitting in this context because it conveys a proactive message to the aircrew that requires immediate attention regarding the intercepted signal. An alert implies a specific acknowledgment of a situation that could necessitate further action or examination, which is crucial in environments where timely and accurate responses can impact safety and operational effectiveness.

Typically, in systems that involve monitoring or interception, alerts are designed to effectively communicate important information that indicates a significant event or condition. An alert can convey more urgency than other terms, suggesting that the aircrew may need to respond or modify their actions based on the information received from the ECU.

In contrast, terms like alarm, warning, or notification may not carry the same immediate connotations of action or urgency as "alert" does in this context. Each of those options has distinct implications and uses in operational language, but "alert" stands out in scenarios where quick comprehension and reaction are vital.