air travel; air trip
General term for traveling by air; can refer to the journey itself or the concept of flying.
空の旅は快適でした。
The air travel was comfortable.
彼は空の旅が好きだ。
He likes air travel.
Compound of 空 (そら, 'sky') + の (possessive particle) + 旅 (たび, 'travel'). Literally 'sky's journey'.