fēi / xíng / yuán / yù / dào / rǔ / bái / tiān / kōng / shí / ， / bì / xū / lì / jí / gǎi / biàn / háng / xiàn / 。

飞行员遇到乳白天空时，必须立即改变航线。

When pilots encounter a whiteout, they must immediately change course.