Abstract: Performance ranking of civil aviation engine based on surveillance information can provide the degree of engine deterioration and stagger difference, make optimal maintenance plan, and reduce maintenance cost.Therefore it has become a critical issue in improving fleet management.However rational methods for evaluating engine's overall performance in civil aviation management are unavailable.This paper establishes a theoretical model and proposes an algorithm to distribute all parameter weights based on a fuzzy equivalent aggregation technique and attribute information entropy of rough set theory when multi-attribute weight information are unknown.As an example, the algorithm has been verified in performance ranking of ten CF6 engines from a civil aviation company.The result shows that the method is objective and effective.

Key words: multi-parameter, aeroengine, performance ranking, fuzzy theory, information entropy