What action is required if mast moment indicator reaches 77% or higher?

• A. No action
• B. Notify maintenance only
• C. A logbook entry only
• D. A logbook entry and maintenance action

Answer: (D)

When the mast moment indicator reaches 77% or higher, it shows the rotor mast is under an over-limit load and could be on the edge of a safety boundary. This calls for a immediate, dual response: officially record the event in the maintenance log and carry out the prescribed maintenance action to inspect and address the condition. Documenting the event creates a traceable record for safety and regulatory compliance, while the maintenance action ensures the root cause is checked and corrected before the aircraft flies again. Doing only one part falls short: logging without repair leaves the issue unaddressed, and repairing without documenting can miss important history. The safest and most thorough approach is to log the event and perform the necessary maintenance.