Which transponder code represents unlawful interference?

Which transponder code represents unlawful interference?

• A. 7500
• B. 7600
• C. 7700
• D. 0000

Answer: (A)

Transponder codes, or squawk codes, are a quick way for a pilot to signal a specific state to air traffic control. The code used to indicate unlawful interference, such as a hijack, is 7500. Setting this code immediately alerts controllers that the aircraft is in a hijack situation, prompting hijack procedures and priority handling from ATC and responders. The other codes map to different situations: 7600 means radio communications failure, so ATC will attempt to reestablish contact by alternative means; 7700 indicates a general emergency, triggering emergency services and priority for the flight; 0000 is not a standard active-code for an in-flight incident and is not used to signal unlawful interference.

Transponder codes, or squawk codes, are a quick way for a pilot to signal a specific state to air traffic control. The code used to indicate unlawful interference, such as a hijack, is 7500. Setting this code immediately alerts controllers that the aircraft is in a hijack situation, prompting hijack procedures and priority handling from ATC and responders. The other codes map to different situations: 7600 means radio communications failure, so ATC will attempt to reestablish contact by alternative means; 7700 indicates a general emergency, triggering emergency services and priority for the flight; 0000 is not a standard active-code for an in-flight incident and is not used to signal unlawful interference.