Definition
Describes a bird that is currently in the process of flying.
（鸟）飞行中
We could see the seagulls on the wing as we arrived.
我们抵达时可以看到海鸥正在飞行。
The eagle was on the wing, circling in the sky before suddenly diving down.
那只老鹰正在飞行，在空中盘旋，然后突然俯冲而下。
Several birds were on the wing, flying above the trees.
几只鸟正在飞行，飞越树林上方。