Viable Opportunity for Fielding an Aircraft Structural Health Monitoring System

Abstract

An important trend in the sustainment of aircraft is the transition from preventative maintenance to Condition Based Maintenance [CBM]. For CBM it is essential that the actual system condition can be measured and that the measured condition can be reliably extrapolated to a convenient moment in the future in order to facilitate the planning process while maintaining flight safety. Much research effort is currently being put in the development of technologies that enable CBM, including Structural Health Monitoring [SHM] systems. Good progress has already been made when it comes to sensors, sensor networks, data acquisition, models and algorithms, data fusion/mining techniques, etc. However, the transition of these technologies into service is very slow. Reasons are that business cases are difficult to define and that certification of SHM systems is very challenging. This paper describes a possibility for fielding an SHM system on legacy aircraft with a minimum amount of certification issues and with a good prospect of a positive return on investment. For appropriate areas in the airframe of an aircraft, the application of SHM will reconcile the fail-safety and slow crack growth damage tolerance approaches that can be used for safeguarding the continuing airworthiness of these areas, combining the benefits of both approaches and removing the drawbacks.