增加一个桨叶(主桨有5个叶片，尾桨有4个)，并使用了改进的排气系统。
Adding a rotor blade (it had five on the main rotor and four on the tail) and using a modified exhaust system were among them.
实验中对涡轮叶片采用四排气膜孔的冷却方案，气膜孔为圆柱形。
The surface of a gas turbine blade was cooled by four rows of cylindrical holes in the experiment.
结果表明，该叶片掉块性质为烧蚀掉块，烧蚀掉块的原因是叶片排气边局部出现瞬时高温。
High temperature of the local exhaust edge of the vane led the vane to ablate and fracture.
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