Landing Gear Leg Fatigue Life Analysis for Light Aircraft

Abstract

Light aircraft, designed for training and recreational purposes, have vital components subject to hard time replacement intervals. Given the wide spectrum of operational conditions those aircraft are exposed to, such a maintenance strategy is not optimal since it is not uncommon for the light aircraft owner to also be the pilot and person in charge of maintenance. Fatigue damage is known to be the primary cause of component failure. Component replacement is a common way of avoiding fatigue damage. Accumulated fatigue damage can be expressed through a quantitative variable dependent on many factors; besides component geometry and material properties, aircraft takeoff mass and component load profile play a key role in fatigue life determination. This research aims at providing insight into the interdependence and relationship between fatigue relevant parameters and the fatigue life of a light aircraft landing gear leg to enhance the understanding of input variables and results enabling the improvement of the method for fatigue life prognosis of a light aircraft landing gear leg. Correlation analysis is performed first. The covariance matrix, Pearson's and Spearman's correlation coefficients, correlation statistics, and scatter plot matrices are observed and discussed to establish joint variability of dependent and independent variables. Regression analysis is applied next. Analysis of variance, R-squared statistics, and residual assessment are performed to evaluate the impact on the dependent variable, gaining insight into how well the regression model explains data variability. Shortcomings of the applied methodology and consequent analysis results are identified and discussed. Lastly, a suggestion based on the findings of this research aimed at validating and improving the method for light aircraft landing gear leg fatigue life calculation is stated.