What is the primary purpose of an annunciator system in an aircraft?

The primary purpose of an annunciator system in an aircraft is to indicate system parameters needing crew attention. This system is designed to enhance safety and situational awareness by providing visual and sometimes audible alerts to the flight crew regarding the status of various aircraft systems. When an issue arises, such as engine problems, hydraulic failures, or other anomalies, the annunciator system will illuminate specific indicators or lights, allowing the crew to quickly identify and address any potential issues before they escalate into more significant problems.

Other options, while relevant to aircraft operation, do not directly pertain to the primary function of an annunciator system. For instance, measuring altitude changes is accomplished through altimeters, and providing weather updates is typically managed through other onboard systems or external services. Showing fuel levels might be part of the cockpit displays, but these gauges are separate from the annunciator system's critical role of warning and alerting the crew to system concerns.