This paper simply analysed basic conditions and velocity range in various weights of helicopter formation flight in single engine operative and performance prediction in specific weight.

本文对直升机单发编队飞行执行某任务的基本条件，不同重量时单发飞行的飞行速度范围，特定重量的性能估算进行了简单的分析。

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Two-stroke engine has its intrinsic advantages in terms of high specific power, compactness, light weight, low cost, etc.

二冲程汽油机具有升功率大、机械损失小、结构简单、制造成本低以及便于维修等特点。

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