Optimal replacement of safety-critical aircraft parts with utilization uncertainties

Two maintenance optimization programs have been proposed to find the optimum lifetime limits of turbine wheels, a safety-critical component in the aircraft engine. The deterministic model enables us to quickly calculate the optimum replacement time provided that the accurate cumulative operating hours are available for the critical components. When the component operating hours involve utilization uncertainties, the stochastic model has been demonstrated as an effective method in terms of finding the optimum age-based replace time. The result is accurate as compared to the solutions form Monte Carlo simulations.