Abstract: Based on a large amount of statistical data, the reliability and maintainability ( R & M)par ameter systems of for eign helicopters and their applicability are discuseed, and their basic train of thought and central points are analysed as well. In light of the feature of engineering developmentin our country, the basic principles, procedures and methods of establishing the R&M parametersystem for newly developed helicopters are pr esented and could be used in engineer ingpractice.

Key words: helicopters, reliability, maintainability, parameters, systems.