What are the four squawk codes for emergency situations?

The four squawk codes designated for emergency situations are 7700, 7600, 7500, and 7777. Each code serves a specific purpose in aviation communications and identifies a type of distress or need for assistance.

The code 7700 is used to indicate a general emergency, signaling air traffic controllers that an aircraft is experiencing a situation that requires immediate attention. This could involve any number of serious issues, such as mechanical failure, fuel emergencies, or medical situations onboard.

Squawk code 7600 is assigned for situations involving radio communication failure. If a pilot loses the ability to communicate with air traffic control but is still able to navigate and fly, using this code alerts controllers that the pilot may not be responding due to a technical issue rather than a more severe emergency.

Code 7500 is specifically used to indicate a hijacking or unlawful interference with the aircraft. This alert informs air traffic control and other relevant authorities about the serious threat to the safety of the flight and allows for coordinated responses to ensure passenger safety.

While the fourth code, 7777, is not standard for emergency situations (it is used for military aircraft), the trio of 7700, 7600, and 7500 clearly designates the essential