Abstract: System and methods for servicing and monitoring shock struts are provided. A shock strut servicing assistance system may comprise: a controller in electronic communication with a display; and a tangible, non-transitory memory configured to communicate with the controller, the tangible, non-transitory memory having instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations comprising: calculating, by the controller, a dead volume of a shock strut and determining, by the controller, a first decision, the first decision being whether or not the dead volume of the shock strut is negative. A shock strut servicing assistance system may be for servicing a shock strut having a negative dead volume.

Abstract: A method includes detecting at least one position measurement of a separator piston of a pitch trim actuator. The method includes detecting at least one pressure measurement of a gas. The method includes detecting at least one temperature measurement of the gas. The method includes storing at least one position value based on the at least one position measurement of the separator piston, at least one pressure value based on the at least one pressure measurement of the gas and at least one temperature value based on the at least one temperature measurement of the gas. The method includes determining a volume of an oil within an oil chamber of the pitch trim actuator and a pressure of the gas within the gas chamber of the pitch trim actuator, based on the at least one position value, the at least one pressure value and the at least one temperature value.

Abstract: Methods for servicing shock struts are provided. In various embodiments, a method for servicing a shock strut may comprise deflating the shock strut; compressing the shock strut until the shock strut is in a fully compressed position; and charging the shock strut with a liquid until a pressure of the liquid decreases a volume of a residual air located inside of the shock strut. In various embodiments, charging the shock strut with liquid under pressure may reduce the volume of trapped air inside of the shock strut to a negligible volume, eliminating the servicing variations.

Abstract: System and methods for servicing and monitoring shock struts are provided. A method for servicing a shock strut may include calculating a first fluid level; generating a first datum corresponding to the first fluid level; moving fluid into the shock strut in accordance with the first datum; calculating a second fluid level; generating a second datum corresponding to the second fluid level; and storing a final fluid level.

Abstract: The present disclosure includes methods for servicing shock struts. Such shock struts may be “air over oil” type, having a gas portion and a liquid portion of a sealed fluid chamber. Methods in accordance with the disclosure include pressurizing the gas portion to a first pressure, then pressurizing the liquid portion until a final pressure is achieved in the gas portion.

Abstract: A method of servicing a shock strut of a landing gear includes partially filling the shock strut with fresh oil and pressurizing the chamber with gas. The pressurizing is to a pressure level that compensates for expected gas pressure loss due to gas entrainment in the oil during operation of the shock strut. The method can be performed without weight on wheels, with weight on wheels and a constant strut stroke, or weight on wheels and a constant pressure.

Abstract: A method and system of monitoring condition of a shock strut senses gas temperature, gas pressure, and stroke of the strut during a landing event. Oil loss is determined based upon a deviation of a transient pressure coefficient derived from transient gas pressures at two different strokes from a nominal coefficient value. Gas loss is determined based upon a temperature adjusted transient gas pressure at a selected stroke and a nominal gas pressure value at the selected stroke.

Abstract: The present disclosure includes methods for servicing shock struts. Such shock struts may be “air over oil” type, having a gas portion and a liquid portion of a sealed fluid chamber. Methods in accordance with the disclosure include pressurizing the gas portion to a first pressure, then pressurizing the liquid portion until a final pressure is achieved in the gas portion.

Abstract: A method includes detecting at least one position measurement of a separator piston of a pitch trim actuator. The method includes detecting at least one pressure measurement of a gas. The method includes detecting at least one temperature measurement of the gas. The method includes storing at least one position value based on the at least one position measurement of the separator piston, at least one pressure value based on the at least one pressure measurement of the gas and at least one temperature value based on the at least one temperature measurement of the gas. The method includes determining a volume of an oil within an oil chamber of the pitch trim actuator and a pressure of the gas within the gas chamber of the pitch trim actuator, based on the at least one position value, the at least one pressure value and the at least one temperature value.

Abstract: A method and system of monitoring condition of a shock strut senses gas temperature, gas pressure, and stroke of the strut during a landing event. Oil loss is determined based upon a deviation of a transient pressure coefficient derived from transient gas pressures at two different strokes from a nominal coefficient value. Gas loss is determined based upon a temperature adjusted transient gas pressure at a selected stroke and a nominal gas pressure value at the selected stroke.

Abstract: A system and various methods for monitoring and evaluating the health of a shock strut assembly are illustrated. Multiple sensors, including gas temperature, gas pressure, oil pressure, and position sensor, may be used to gather data and evaluate the performance of the shock strut assembly. Various methods illustrated herein may evaluate the dynamic damping, static load support, and/or controlled stroke performance of the shock strut assembly.

Abstract: A method of servicing a shock strut of a landing gear includes partially filling the shock strut with fresh oil and pressurizing the chamber with gas. The pressurizing is to a pressure level that compensates for expected gas pressure loss due to gas entrainment in the oil during operation of the shock strut. The method can be performed without weight on wheels, with weight on wheels and a constant strut stroke, or weight on wheels and a constant pressure.

Abstract: A monitoring system for a landing gear system comprising a plurality of sensors for monitoring respective parameters of the aircraft landing system, and a monitor which receives the outputs of the sensors.