Based on the statistics of the troubles that happened in a given engine including their times

the appearances

the reasons

the characters

as well as the measure and the time for eliminating

quantitative analyses of the troubles have been made

and the variable relationships of the trouble-frequency with engine sample

engine operation time section and properties of the trouble have been found out.The monographic analysis has been focussed on the repeated failure and major failure.The reliability and maintainability index of the given engine have been evaluated.Finally

precautions during field maintenance are discussed

some suggestions are presented for its modification and production.