What part of the FADC/LOCOP allows watchstanders to view operational parameters?

• A. Analog gauge panel
• B. Pneumatic starter
• C. Start air regulator
• D. Human machine interface (HMI)

Answer: (D)

The interface that lets watchstanders see how the system is running is the Human Machine Interface. The HMI is the digital display and control panel that shows real-time operating data—such as speeds, temperatures, pressures, and status alarms—in a clear, readable format, and it lets operators interact with the system as needed.

The other parts have distinct roles: an analog gauge panel can display some readings but is limited and less capable of presenting the full set of parameters and alarms; a pneumatic starter provides the mechanical/startup power; a start air regulator manages the air supplied to the starter. So, for viewing operational parameters, the HMI is the primary, purpose-built interface.