n.飛行器的起落架；底架；下架

The undercarriage was fully retracted. 起落架被完全收起。

Undercarriage appeared to be down and in place. 起落架已放下在正常位置。

The pilot found that the undercarriage could not be retracted. 飛行員發(fā)現(xiàn)飛機的起落架不能縮回。

The undercarriage on light aircraft does not always retract in flight. 輕型飛機飛行時起落架不一定縮回。