Health monitoring in landing gears

Every mechanical construction loses its properties in time due to the usage wear that leads to malfunctions and, in the end, to failure. Widely used method of failure time prediction base on extended laboratory tests where a device is tested against fatigue and wear. This method is well established but is expensive, time-consuming, and costly. Another way of failure prediction is to calculate it using advanced algorithms what is faster and cheaper but less accurate than actual tests. Furthermore, both methods are not optimal due to the principle of operation based on simplified assumptions. In such cases, it is common to make the lifespan of the safety wise devices for example landing gears much less than real in case of fatal failure not covered by the predictions. This can lead to much higher price and maintenance costs of the landing gear. Nowadays the worldwide trend is to monitor the behaviour of the devices in real time and predict failure using actual state. There are several methods of health monitoring, most of them including sensors, acquisition systems and computer software for analysis. In this article, authors describe possible landing gears health monitoring methods based on authors’ laboratory experience in sensor appliance and test data analysis. The authors also present their idea of adding health monitoring to existing landing gears where no dedicated infrastructure was initially designed.