When should a controlled transfer of an aircraft occur?

A controlled transfer of an aircraft typically occurs at a designated point or specific criteria, such as a prescribed Fix, Location, Altitude, or Time. This structured method ensures that there is a clear understanding of when the responsibility for the aircraft changes from one controller to another, maintaining safety and continuity of service.

Establishing a defined moment for transfer, such as at a specific fix or altitude, allows both controllers to coordinate the transition effectively, ensuring that the aircraft is under the appropriate guidance at all times. This method minimizes the risk of miscommunication and enhances situational awareness for all parties involved.

The other options do not represent the standard practices for controlled transfers. Conducting transfers only during adverse weather conditions is not a routine procedure; such conditions may require additional considerations but do not dictate when transfers should occur. Changing squawk codes is an operational task but does not inherently signal a controlled transfer of responsibility. Finally, allowing transfers at any time during the flight can lead to confusion and potential safety risks, as it does not establish clear communication and protocol, which are essential for managing air traffic effectively.