If no data has been received for approximately how many minutes, Line 10 on the tower cab display will indicate COMMUNICATION FAILURE?

• A. 1 minute
• B. 2 minutes
• C. 5 minutes
• D. 10 minutes

Answer: (B)

Data feed timeouts trigger the COMMUNICATION FAILURE alert when the incoming data on Line 10 stops for a short, defined period. About two minutes is used here because it quickly flags a real data link problem without reacting to brief network hiccups or momentary delays that can happen in normal operation. If the data resumes within that window, the alert would clear automatically; the system only marks a failure after the two-minute threshold is reached. A shorter timeout would cause alarms too often for minor interruptions, while a longer one would delay awareness of actual failures, potentially impacting safety and operations.