Before reaching the FAF for a coupled ILS approach, what must you do?

Before reaching the Final Approach Fix (FAF) for a coupled Instrument Landing System (ILS) approach, it is essential to advise Air Traffic Control (ATC) that you are conducting a coupled approach. This communication ensures that ATC is aware of your intention to utilize the autopilot for the approach, which can be critical for maintaining situational awareness in busy airspace and for ensuring that any required separation from other aircraft is maintained.

Notifying ATC about your approach method allows them to provide the necessary traffic advisories and allows other aircraft in the vicinity to be aware of your approach, facilitating safe and effective air traffic management. This step is crucial, especially in controlled airspace where multiple aircraft might be operating on similar or intersecting flight paths.

In contrast, while confirming altitude, reducing speed, and changing approach configuration are important tasks during the approach, these actions are not specifically required to be done before reaching the FAF in the context of coupling the approach. They may be routine aspects of preparing for landing but do not replace the need for notifying ATC of the flight mode being used.