Life and Reliability Prediction for Turbopropulsion Systems

The predictability in assessing an engine"s shop direct maintenance cost is largely a result of the significant reliability improvements inherent in today"s engine technology and a result of the introduction of on-condition maintenance. Engine on-condition maintenance seeks to do away with"hard-time"interval removal and prescribes routine monitoring of key operational parameters to drive removal. A by-product of these reliability improvements and the on-condition maintenance philosophy is a greater reliance on software and statistical analysis to predict the frequency of engine shop visit events and their corresponding shop visit costs. Estimating an appropriate direct maintenance cost therefore, requires careful forecasting of the equipments on-wing life as well as an accurate assessment of its capability to achieve that life and understanding the costs involved in improving that capability. The requirement of any reliability software is to be able to statistically describe any of the data elements that can be used to drive a prediction of on-wing life and/or identify direct maintenance cost. This multi-faceted approach can then provide useful information to optimization software, cost or ATOW forecasting software or other useful tools that will provide engine program management and their customers the ability to accurately assess the condition of fielded systems, understand their capabilities and identify long term management needs to maintain and improve the performance of these systems through out their intended life and beyond.