The plane returned to the air in December after being grounded for 20 months in the US following two deadly plane crashes, while Boeing fixed a software glitch tied to both air disasters and retrained pilots.
這架飛機在美國發生兩起致命的空難後停飛20個月,於12月重返空中,而波音公司則修復了與這兩起空難有關的軟件故障,並重新培訓了飛行員。