noun, noun which may take the genitive case particle 'no'
low altitude; low sky
Refers to a low altitude or the sky near the ground. Often used attributively with の to modify nouns like 飛行 (flight) or 雲 (clouds).
飛行機が低空を飛んでいる。
The airplane is flying at a low altitude.
Low clouds are hiding the mountain top.
低空 describes flying or being at a low altitude, the opposite of 高度 in the sense of altitude.
low-altitude flying; flying at low altitude · barely scraping by; consistently poor results; on the verge of failing
Compound of 低 (low) and 空 (sky). The reading ていくう is the standard on'yomi combination.