As to the selection of rotor blade number for light and medium helicopter, 4 blade and 5 blade rotor are typical.

而旋翼桨叶片数的选择，对轻型和中型直升机来讲，4片桨叶旋翼和5片桨叶旋翼具有典型意义。

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The comparative tests of the pinrotor with conventional two blade rotor in a domestic internal mixer were reported.

本文介绍了在国产密炼机上采用销钉转子和普通二棱转子进行对比试验的情况。

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Then there's increasing the number of rotor blades. This helps because each additional blade carries less of the weight of the helicopter, and thus produces less noise.

增加旋翼桨叶数量也是一种方法，这使得每片桨叶负载的直升机重量降低了，因此产生的噪音更小。

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Each blade on the three-blade rotor is to be 150 feet long.

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Islami said the rotor blade snapped off, the copter spun to the ground and burst into flames.

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The Air Accidents Investigation Branch (AAIB) found there was a rotor blade fault that caused them to strike the craft and separate.

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