US Patent 11981424 Trend monitoring of a shock absorber condition

A method of monitoring the condition of an aircraft landing gear shock absorber, the shock absorber including at least one spring chamber containing a gas, the method comprising taking a plurality of measurements of the gas pressure and temperature, each gas pressure and temperature measurement pair being taken of at the same instant relative to an operating cycle of the shock absorber; calculating, based on each pair of gas pressure and temperature measurements, a first value; storing the first value in a log; determining a value trend based on the log; and in response to determining that the value trend is outside a first range of values, generating a first notification signal.