What is the purpose of a master caution indicator during electrical faults?

• A. To alert crews to malfunctions that require attention and troubleshooting.
• B. To power down affected systems automatically.
• C. To diagnose faults and automatically repair them.
• D. To log faults for maintenance records only.

Answer: (B)

The master caution indicator is there to alert crews to faults that need attention and troubleshooting. When an electrical fault occurs, the amber master caution light signals that something is out of normal range and requires crew action. It prompts you to review the fault messages, assess affected systems, and follow procedures to isolate and diagnose the issue.

It does not automatically power down systems—that function is handled by protective logic or autoselection/ interlock systems, not by the caution indicator itself. It also does not diagnose or repair faults, nor is it simply a log for maintenance records. The light is essentially a wake‑up call to prompt timely crew intervention and systematic troubleshooting.