In MSSR, when the operational on-line channel fails, what happens?

• A. The standby channel remains off-line until manual reset
• B. The standby channel comes on-line and the faulted channel goes off-line not to exceed 4 seconds
• C. The faulted channel remains online and reduces performance
• D. The system shuts down completely

Answer: (B)

When a system uses dual redundant channels, it is designed to switch automatically to a standby path if the primary on-line channel fails. In MSSR, the standby channel comes online and the faulted (failed) channel is taken offline, with the switchover completed in not more than about four seconds. This keeps the radar system operating with minimal interruption.

The other possibilities would require manual intervention (staying offline until reset), would keep the faulted channel online and merely degrade performance, or would shut the system down entirely—none of which align with automatic failover that preserves continuous operation.