air transportation; air transport
Refers to the transport of goods or passengers by aircraft. Often used in logistics and business contexts.
This cargo will be sent by air transport.
The cost of air transportation is higher than sea transport.
海運 refers to transport by sea, while 空運 refers to transport by air.
Compound of 空 (kuu, 'sky, air') and 運 (un, 'transport, carry'). The exact historical derivation is uncertain, but the word follows the pattern of other transport terms like 海運 and 陸運.