The priority level of the battery discharge messages that were provided by the engine indicating and crew alerting system did not accurately reflect the risk presented by the battery discharge status.
The issue cannot be directly addressed without significant redesign of the EICAS.
The ATSB reminds operators and flight crews of transport category aircraft that although battery discharge may occur routinely, immediate flight crew action may be necessary in the event of abnormal or unexpected battery discharge alerts if the battery discharge status cannot be immediately resolved in-flight. Multiple electrical system failures, including failures of critical flight systems, may occur in the event of battery power depletion.
The ATSB recognises that any change in the priority level of the battery discharge messages would contradict the EICAS priority level definitions if no crew actions were associated with the message entries in the QRH. Accordingly, the priority level and QRH should be assessed concurrently. However, the risk presented by the potential for the battery discharge message to be overlooked in the event of multiple EICAS messages remains significant.
