How are redundancy checks incorporated into CSOSS sequences?

• A. Redundancy is ignored to simplify decisions.
• B. Sequences include checks for redundancy, and operators may switch to alternate sources if primary fails, following preset procedures.
• C. Redundancy requires all sources to be used simultaneously.
• D. Redundancy is only considered during maintenance.

Answer: (B)

Redundancy in CSOSS sequences is built in by making checks for the available primary source part of the standard procedures and providing predefined steps to switch to backup sources when the primary fails. Each sequence includes status verifications (such as whether the primary source is online and healthy) and clear actions to move to an alternate source if needed, all following preset corrective steps. This design ensures continuous operation of critical systems, minimizes downtime, and keeps crew actions consistent and safe under fault conditions. Other approaches that ignore redundancy, require all sources to be used at once, or only consider redundancy during maintenance don’t reflect how CSOSS structures real-time, fail-safe operation.