Financial and risk assessment and selection of health monitoring system design options for legacy aircraft

摘要

Aircraft operators demand an ever increasing availability of their fleets withconstant reduction of their operational costs. With the age of many fleetsmeasured in decades, the options to face these challenges are limited.Integrated Vehicle Health Management (IVHM) uses data gathered throughsensors in the aircraft to assess the condition of components to detect andisolate faults or even estimate their Remaining Useful Life (RUL). Thisinformation can then be used to improve the planning of maintenanceoperations and even logistics and operational planning, resulting in shortermaintenance stops and lower cost. Retrofitting health monitoring technologyonto legacy aircraft has the capability to deliver what operators and maintainersdemand, but working on aging platforms presents numerous challenges. Thisthesis presents a novel methodology to select the combination of diagnostic andprognostic tools for legacy aircraft that best suits the stakeholders’ needs basedon economic return and financial risk. The methodology is comprised ofdifferent steps in which a series of quantitative analyses are carried out to reachan objective solution. Beginning with the identification of which componentscould bring higher reduction of maintenance cost and time if monitored, themethodology also provides a method to define the requirements for diagnosticand prognostic tools capable of monitoring these components. It then continuesto analyse how combining these tools affects the economic return and financialrisk. Each possible combination is analysed to identify which of them should beretrofitted. Whilst computer models of maintenance operations can be used toanalyse the effect of retrofitting IVHM technology on a legacy fleet, the numberof possible combinations of diagnostic and prognostic tools is too big for thisapproach to be practicable. Nevertheless, computer models can go beyond theeconomic analysis performed thus far and simulations are used as part of themethodology to get an insight of other effects or retrofitting the chosen toolset.