breakdown crane是什么意思

用法例句

At the same time, the paper studies the origin of emergency takeoff - landing or takeoff reserve runway s clearance specifications by using the theory of takeoff-landing path of aircraft.

从备用跑道用途及其净空规定出发,指出现行备用跑道净空规定存在的问题,提出备用跑道净空区的组成和要求,并应用飞机起落航线理论,对应急起飞着陆及应急起飞备用跑道净空规格的来源进行了研究。