The aircraft hangs out the 7700 emergency code to indicate that the aircraft is experiencing an emergency.
When pilots encounter special circumstances during flight, they will set the response code to a special code. This special coding allows the aircraft to be distinguished as a red mark in the air traffic control radar system, reminding air traffic control personnel and other air crews to pay attention to avoidance. In the event of a hijacking, the pilot will set the transponder to 7500.
Extended information:
In flight, the emergency code "7700" has two meanings. One is that the aircraft has a mechanical failure in the air, and the other is that a medical emergency has occurred. .
Chen Jianguo said that as the captain, when encountering an emergency such as landing gear failure, it is necessary to promptly send a "special code" to the ground. After the crew sends the signal, the ground radar will receive a warning, and the control department will quickly inquire and investigate the status of the aircraft, so as to quickly activate the ground emergency plan according to the aircraft situation and ensure the safe landing of the aircraft as much as possible.
Lawyer Zhang Qihuai, an aviation law expert, said that 7700 is the international default emergency distress signal. When an aircraft is in danger, the signal is sent out through a high-frequency transponder that is always in contact with the ground. All countries on the ground monitor it. will receive a red alarm.
After receiving the signal, aircraft from other countries in the relevant area on the ground will respond and provide "priority" for the emergency signal. Simply put, the emergency code 7700 is "very noisy". After landing, the National Civil Aviation Administration and the local Civil Aviation Administration will rush to the scene as soon as possible to investigate the crew that issued 7700 to understand the cause of the accident.
Baidu Encyclopedia-7700 Emergency Code
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