What does the CA of flight CA43 12 mean?

For the convenience of transportation and users, each flight has a flight number. China international flight number consists of two-character codes and three Arabic numerals of the airline performing the flight mission, of which the last digit is odd, indicating the departure flight, and the last digit is even, indicating the return flight. For example, CA98 1 refers to the international flights from new york to Beijing undertaken by China International Airlines. The flight number of domestic flights in China consists of the two-character code of the airline carrying out the flight mission and four Arabic numerals, in which the first digit indicates the airline carrying out the flight mission or its administration, the second digit indicates the administration of the flight terminal, and the third and fourth digits indicate the frequency, that is, the specific number of the flight. If the fourth digit is odd, it means that the flight is an outbound flight, and if it is even, it is a return flight. For example, CA 120 1 represents the departure flight from Beijing to Xi 'an provided by China International Airlines, and MU5302 represents the return flight from Changsha to Shanghai provided by Eastern Airlines. Attachment: The two-character code of some domestic airlines and the code of Civil Aviation Administration of China China International Airlines CA North China Administration 1 China Northwest Airlines WH Northwest Administration 2 China Southern Airlines CZ Guangzhou Administration 3 Shenzhen Airlines H4 3 China Southwest Airlines SZ Southwest Administration 4 Sichuan Airlines 3U 4 Yunnan Airlines 3Q 4 China East. Fang Airlines Mu Huadong Administration Bureau 5 Shanghai Airlines SF 5 China Northern Airlines CJ Shenyang Administration Bureau 6 China General Aviation GP 7 Xiamen Airlines MF 8 Xinjiang Airlines XO