In "RADAR CONTACT", which reports must be made to ATC or FSS without a specific request?

When it comes to reporting requirements in relation to "RADAR CONTACT," it is essential to understand the contexts in which specific reports are mandatory for the safety and coordination of air traffic. The correct answer highlights important aspects of reporting related to air traffic management.

The reasoning behind the choice that covers both leaving a holding fix and when an approach has been missed lies in the established protocols designating significant phases of flight. When a pilot exits a holding pattern, it signals to air traffic control (ATC) that they are proceeding with their flight plan, which requires affirmation and tracking by ATC to maintain safe separation from other aircraft.

Similarly, notifying ATC when an approach has been missed is crucial because it affects the aircraft's subsequent actions, allowing ATC to provide guidance or traffic advisories as the pilot may need to perform a missed approach procedure. This helps ensure that all aircraft in the vicinity are properly informed and that appropriate measures are taken to maintain overall safety.

In contrast, while entering controlled airspace or requesting a frequency change are important communications, they don't carry the same weight in terms of required reporting without a specific request. Entering controlled airspace should already be part of the clearance given, while a frequency change is typically initiated by the pilot when