第五级属于高级程度，使操控者有能力执行基础的后退飞行。

The level of a pilot capable of performing beyond the basics of Backward Flight.

youdao

第五级属于高级程度，使操控者有能力执行基础的后退飞行。

The level of a pilot capable of performing beyond the basics of Backward Flight.

youdao