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。

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.

youdao

虽然与直升机外观相似，但自转旋翼机必须依靠向上流过桨叶地气流维持旋翼地旋转，产生将飞行器维持在空中地升力以及向前飞行地推力。

While similar to a helicopter rotor in appearance, the autogyro's rotor must have air flowing up and through the rotor disk in order to generate rotation.

youdao

他还设计过带有旋转翼的飞行器模型，与今天的直升机很相似。

He also designed the prototype for a flying machine with a rotating wing similar to today's helicopters.

youdao