the max speed of UAV

[shenwenxiao]

I control the UAV by python API 'moveByVelocityAsync'， the code is:
client.moveByVelocityAsync(vx,0,0,1)
I find that whatever the speed "vx" is , the UAV in UE4 fly with the same speed. vx=10, vx=50, or vx=100, the UAV fly with the same speed.
It seems that there is a maximum flying speed constraint. Is it right? How much is the maximum flying speed?