What phrase should be used in a report on position to ATC when in radar contact?

Using the phrase "RADAR CONTACT" in a report to Air Traffic Control (ATC) indicates that an aircraft is currently being tracked by radar and is within the radar coverage area. This phrase confirms to the ATC that the aircraft's position is being monitored, allowing for more precise and efficient communication and navigation.

In radar contact, the controller has the capability to provide guidance and information based on the aircraft's current position, enhancing situational awareness for both the pilot and ATC. This phrase also facilitates the continuity of services as radar information is exchanged, helping to ensure safe operation within controlled airspace.

The other choices, while relevant in certain contexts, do not convey the same level of specific information about the aircraft's surveillance status. "POSITION REPORT" is typically used when pilots report their location without radar assistance. "ATIS INFORMATION" refers to automatic terminal information service, which provides essential non-traffic information. "RADAR SERVICE TERMINATED" indicates that radar services are no longer being provided, which would not be applicable when in radar contact. Thus, "RADAR CONTACT" is the appropriate choice when a pilot is confirming their radar status to ATC.