Remaining life assessment methodology for aged aircraft fleet

World experience in last few decades has shown that aircraft usage varies from aircraft to aircraft, mission to mission and user to user. This paper describes the procedure to predict the remaining life of an in service aircraft based on the data from onboard flight data recorders. The proposed method uses 'rain flow cycle counting' and 'Palmgren-Miners' techniques to correlate flight parameters with usage frequency for structural life prediction and computes the impact of the actual loads resulting in 'strength degradation' and 'expected remaining life'. It identifies the most stressed areas along with fatigue life cycles thus estimating the remaining life cycles. The data acquired through the successful application of proposed methodology is also assistive in determining the maintenance cycle and its revision, which is a major cost driver during operations. The results attained through computations directly correspond to the severity of usage.