FAILURE MODE IDENTIFICATION AND DATA PREPARATION FOR AEROENGINE RELIABILITY STUDIES

Failure prediction and evaluation of operational reliability of aeroengines is an important activity for the fleet management. Studies have been reported in the literature on the reliability analysis of components and systems but publications on data preparation, validation etc. which is a prerequisite for successful reliability evaluation is scarce. Failure mode identification and data preparation assumes greater significance due to the fact that the utility of the outcome of statistical analysis for operational decisions is limited by the quality of the data that had gone into the analysis. This paper presents the study carried out on failure mode identification and data preparation for reliability analysis of a typical aeroengine operated by the Armed Forces. Operational success of an engine depends on the collective functioning of several components and for evaluating the system reliability, we need to construct a reliability block diagram, by segmenting the physical structure of the engine into modules/sub-systems without loss of vital information on the system. Procedures adopted for segmentation of a complex physical system into a hierarchical structure, consisting of different modules (subsystems /assemblies), which can further be divided into elementary components have been discussed in the paper. It also illustrates the data extraction on inter arrival times, which are either exact or censored, based on the competing risks set-u