What is the transponder code for lost communication?

The transponder code used for lost communication is 7600. This code is specifically designated for situations where an aircraft is unable to establish or maintain communication with air traffic control. When a pilot sets their transponder to 7600, it alerts air traffic control that the aircraft may be experiencing communication difficulties, thus activating specific protocols to ensure the safety and guidance of the aircraft.

This code is part of a standardized system that allows for effective communication and situational awareness between pilots and controllers, enabling quick recognition of issues and appropriate responses. The use of this code is essential for enhancing safety in the operational environment, as it prompts controllers to monitor and assist the aircraft more closely.

Transponder codes serve distinct purposes for different situations: for instance, 7500 indicates unlawful interference (hijacking), and 7700 signifies an emergency that is not necessarily related to communication loss. This structure allows for a clear and immediate understanding of an aircraft's situation.