What should pilots monitor concerning hydraulic systems?

Monitoring pressure levels and fluid leaks in hydraulic systems is critical for pilots because these systems are integral to the operation and safety of the aircraft. Hydraulic systems are responsible for a variety of crucial functions, including controlling the flight control surfaces, landing gear, and brakes.

Pressure levels indicate the functionality and performance of the hydraulic system; if the pressure drops below acceptable levels, it can suggest a potential malfunction or impending failure, which may compromise the control of the aircraft. Additionally, monitoring for fluid leaks is essential as it helps identify any malfunctions early on. A fluid leak can lead to a loss of hydraulic fluid, ultimately resulting in a failure of the hydraulic system, which could endanger the aircraft's operation.

While engine temperature, fuel levels, and weight distribution are important aspects of overall aircraft operations, they do not specifically pertain to the direct performance and integrity of the hydraulic systems. Thus, focusing on pressure levels and fluid leaks is the most relevant and critical aspect for pilots to ensure the safe operation of the aircraft.