E类和A 类空域的划分取决于在这两类空域飞行的飞机类型。
The reason for the division of Class E and Class A airspace stems from the type of planes operating in them.
美国的空域分为21个区域（管制中心），每一个区域都划分为多个扇区。
The United States airspace is divided into 21 zones (centers), and each zone is divided into sectors.
扇区划分是空中交通管理的一项重要工作，它直接影响空域的容量和安全性。
The sector partition is an important work of air traffic management, its operation affects the airspace capacity and security.
美国的空域分为21个区域（管制中心），每一个区域都划分为多个扇区。
The United States airspace is divided into 21 zones ( centers ) , and each zone is divided into sectors.
美国的空域分为21个区域（管制中心），每一个区域都划分为多个扇区。
The United States airspace is divided into 21 zones ( centers ) , and each zone is divided into sectors.
应用推荐