When should you inform an aircraft that radar service is terminated?

Informing an aircraft that radar service is terminated is an essential aspect of air traffic control communication. This typically occurs when an aircraft cancels its IFR (Instrument Flight Rules) flight plan. In busy airspace, other aircraft may rely on radar services for conflict resolution and navigation assistance, so making this termination clear is crucial for maintaining safe airspace management.

When an aircraft cancels its IFR flight plan, it indicates that they are no longer adhering to IFR protocols and will either be transitioning to VFR (Visual Flight Rules) or handling their navigation independently. This necessitates that air traffic control communicate the termination of radar service, as the primary guidance provided under IFR is no longer applicable. This helps ensure that the aircraft understands their responsibility to navigate without radar assistance and is aware of their situation concerning other air traffic.

In other scenarios mentioned, while they involve important communication, they do not signal the same clarity regarding the end of radar service. For instance, exiting uncontrolled airspace typically does not necessitate a radar service termination notice; rather, it indicates a transition in airspace type. Contacting another tower might indicate a change in air traffic control facility but does not by itself require the termination of radar service. Completing a visual approach does not automatically signify that radar