What are ADS-C and CPDLC used for?

• A. Weather data broadcasting.
• B. GPS correction services.
• C. Voice communications for pilots and air traffic control.
• D. Data link communications for automatic position reporting and controller-pilot data link communications.

Answer: (D)

ADS-C and CPDLC are used for data link communications between the aircraft and air traffic control, enabling automatic position reporting and controller-pilot messaging. ADS-C provides automatic, contract-based position reports to ATC—sharing your position, time, altitude, speed, and other flight data on a defined schedule or when a change occurs. CPDLC delivers text-based messages for clearances, routing changes, restrictions, and other routine communications, reducing the need for voice transmissions. Together, they streamline how you exchange surveillance data and flight instructions, improving efficiency and situational awareness. They aren’t used for weather data broadcast, GPS correction services, or voice communications, which are handled by other systems.