They have to wait for clearance from air traffic control.

他们必须等待空中交通管制队下达的起降许可令。

The pilot was given clearance to land by air traffic control.

飞行员得到空中交通管制站发出的着陆许可。

The study says there must be a complete overhaul of air traffic control systems.

研究称必须对航空交通管理系统进行彻底的改革。

Analysts fear the overstretched air traffic control system could reach breaking point.

分析家们担心超出承受能力的空中交通控制系统会接近爆点。

The volume of scheduled flights is straining the air traffic control system.

定期航班的数量使空中交通控制系统受到压力。