What is the difference between ADS-B Out and ADS-B In?

• A. ADS-B Out broadcasts data from other aircraft to your cockpit.
• B. ADS-B Out receives data from other aircraft.
• C. ADS-B Out is used for weather data; ADS-B In is used for traffic data.
• D. ADS-B Out broadcasts aircraft position; ADS-B In receives data from others for display and awareness.

Answer: (D)

ADS-B has two separate functions: Out and In. Out is about you broadcasting your own state to others—your aircraft’s position, speed, altitude, and identification come from onboard sensors and GPS, and that data is transmitted so other aircraft and ground systems can know where you are. In is about receiving information from other aircraft and from services like weather data when available, so you can display traffic and, sometimes, weather on your cockpit displays.

So the difference is that Out transmits your own position, while In receives data from others to help with situational awareness. If a nearby aircraft is shown on your display, that information comes from its Out broadcast being picked up by your In receiver.

The other statements mix up the roles: Out does not broadcast data from other aircraft, and Out does not receive data from others. Weather data can be delivered to In in some setups, but the core distinction is still that Out transmits your own position and In receives others’ data for display and awareness.