The helicopter, named GEN H-4, has a set of two rotors turning in opposite directions and can fly at a maximum speed of 50 kilometres (31 miles) per hour.
这架代号为GEN H - 4的直升机有两个向相反方向旋转的旋翼，最高飞行速度可达每小时50公里。
3
The speed is then about 425 miles per hour so the horizontal component 300mi/h and the vertical component is also 300.