What is measured to determine the proper operating position of an oleo shock strut?

To determine the proper operating position of an oleo shock strut, the extension of the strut is measured. The extension is crucial because it reflects how much the strut has compressed and extended during operation, which is directly related to the aircraft's weight and landing impact. The proper extension ensures that the shock strut functions effectively to absorb shock loads during landings and that the aircraft maintains the correct altitude at which it sits on its landing gear.

While fluid pressure is certainly important to the operation of the strut, it is not the direct measurement used to assess the strut's operating position. Similarly, the weight of the aircraft influences how the strut behaves but is not itself a direct measure of the strut's extension. Temperature of the oil can affect its viscosity and performance but is not used to determine the operating position of the oleo strut. Thus, measuring the extension of the strut provides the most relevant information to ensure optimal performance and safety during operation.