Reliability Analysis of a Helicopter Utility Hydraulic System Using Reliability-centered Maintenance and Bayesian Network

Abstract

Purpose: Reliability-centered maintenance (RCM) provides a standardized procedure for maintenance decision-making. The Bayesian network (BN) is a powerful tool for estimating the posterior probability based on the likelihood and prior probability distribution of failures. This study demonstrates reliability analysis and maintenance decision-making using RCM and BN.BRMethods: Maintenance decisions are made following the RCM framework for the failure of the utility hydraulic system. Bayesian updating and reliability analysis can be performed using the BN model. Real cases of field failure and the survival data of AH-64E were used for this study. The common cause failure (CCF) mode was incorporated into the BN to consider aircraft battle damages.BRResults: Failure diagnostic ability was demonstrated, and the life of the system was obtained. The most effective maintenance action was suggested based on reliability calculation. In addition, the results offered support that CCF should be considered for reliability calculation.BRConclusion: Reliability analysis conducted using RCM and BN can prove beneficial for system-level maintenance decision-making. The BN with CCF revealed unforeseen risks of aircraft battle damage.