When are you considered established inbound?

You are considered established inbound when the Course Deviation Indicator (CDI) comes alive. This indicates that the aircraft is receiving guidance to the inbound course of an approach, meaning that the navigational system has determined that the aircraft is on or near the intended flight path towards the runway. The activation of the CDI shows that the aircraft’s heading is aligned with the approach path, allowing for a controlled descent and guiding the pilot towards the final approach fix.

While reaching the initial approach fix signifies that you are beginning the approach, you are not yet considered established inbound because the aircraft may not be properly aligned with the approach course at that point. Similarly, crossing the Final Approach Fix (FAF) is too late to be considered established inbound, as that point usually indicates the descent to the landing zone has commenced, rather than confirming alignment with the approach path. Finally, air traffic control clearance is essential for legal and procedural reasons but does not directly indicate the technical status of being established inbound in the context of navigation and the CDI's functionality.