What about the flight number of the plane?

The flight number usually consists of two-word code of each airline plus four Arabic numerals. Among them, the two-character code is the abbreviation of airlines, such as CA stands for China International Airlines, MU stands for China Eastern Airlines, CZ stands for China Southern Airlines, HU stands for Hainan Airlines, Shenzhen Airlines, MF stands for Xiamen Airlines, SC stands for Shandong Airlines and 3U stands for Sichuan Airlines. ...

The first of the last four digits indicates the area where the departure base of the airline to which the flight belongs is located; The second place indicates the base area where the terminal of the flight is located; The third and fourth digits indicate the flight serial number: odd numbers indicate the flights departing from the base, and even numbers indicate the flights returning from the outside.

But if you apply the above rules, you may find it impossible to explain the real route of flight CA 1852. With the increasing number of emerging airlines and flights, many flight numbers can no longer apply the original rules. Although the flight number is no longer strictly regulated, it is not "untraceable", and at least two things have not changed.

The two-word code still represents the airline.

The third and fourth places are still flight serial numbers.

Similarly, odd numbers represent flights leaving the base and even numbers represent flights returning to the base.

In addition, the first two digits of the flight number are still related to the base location and destination location of the airline. Judging from the statistics of the first two digits of flights, the rule of "number corresponding area" is still traceable, especially Air China, China Southern Airlines and China Eastern Airlines.

For example, Air China (CA) flights use "1" (originally representing North China Base) the most, accounting for 63%. The flight of China Southern Airlines (CZ) starts with the number "3" (that is, it originally represented the South China base), accounting for 53%. The flight of China Eastern Airlines (MU) starts with the number "5" (which originally stands for East China Base), accounting for 53%.

Although most flight numbers are two-word codes plus four Arabic numerals, you must have met some flight numbers followed by letters. If the flight is delayed, alternate or cancelled due to weather or mechanical failure, it is necessary to make up the flight. In order to distinguish between the original flight and the replacement flight, the airline will turn the last digit of the original flight number into a letter.