American airlift line

Based on Los Angeles and New York, it radiates across the United States, with an overall aging of 10-12 days

Canadian air line

Based on Vancouver and Toronto, the radiation is fully increased, and the overall aging is 10-12 days

British air line

Based on London and Manchester, it radiates all over the UK for 10-12 days.

European air transport line

Based on Paris and Berlin, it radiates all over Europe, with an overall aging of 10-12 days