Longitudinal direction butt joint of gthin gas - in tube on No. 9 helicopter has been welded by use of microplasma arc improved , and results are comfortable.

• 采用高频脉冲微束等离子弧焊接直九飞机薄壁进气道的纵缝对接接头；提高进气道的纵缝焊接质量和产品合格率；得到了满意的结果.