Final answer:
The three Mode 3 emergency codes for aircraft are 7500 (hijacking), 7600 (radio failure), and 7700 (general emergency). These codes inform air traffic control of the type of emergency.
Step-by-step explanation:
The three Mode 3 (or Mode C) emergency codes used by aircraft are 7500, 7600, and 7700. These are squawk codes used in air traffic control transponder systems. Specifically, 7500 indicates a hijacking or unlawful interference, 7600 represents a loss of communication (radio failure), and 7700 denotes a general emergency. These codes clearly explain to air traffic control the kind of emergency the aircraft is experiencing, which is crucial for subsequent rescue procedures.
Learn more about Air Traffic Control Emergency Codes