noun
low-altitude flying; flying at low altitude
Literal aviation term for flying close to the ground or sea surface.
ヘリコプターが低空飛行で山の斜面を調べていた。
The helicopter was flying at low altitude, inspecting the mountain slope.
noun
barely scraping by; consistently poor results; on the verge of failing
Figurative use likening poor performance to flying dangerously low; often used for grades, sales, or approval ratings that are barely above failure.
今学期の成績は低空飛行で、なんとか赤点を免れた。
My grades this semester were barely scraping by; I just managed to avoid failing marks.
新製品の売り上げは低空飛行が続いている。
Sales of the new product continue to barely scrape by.