What are typical indicators of a hydraulic system failure and how would you isolate or mitigate the issue?

• A. Loss of authority, abnormal pressure readings, or unusual system behavior; verify gauges, switch to alternate pumps, isolate the affected system, and follow QRH.
• B. Loss of hydraulic fluid without pressure change; simply recheck later.
• C. Hydraulic failures are not critical and require no action.
• D. Hydraulic issues only affect cabin pressurization levels.

Answer: (C)

Problems with a hydraulic system are critical because hydraulics power essential flight controls, landing gear, brakes, and spoilers. Typical indicators include loss of authority on control surfaces, abnormal or fluctuating hydraulic pressure readings, and unusual system behavior such as warning lights or fluid leaks. To isolate or mitigate, pilots verify the pressure gauges and system indications, switch to available alternate hydraulic pumps to restore pressure, isolate the affected system by using the appropriate valve positions or pump OFF settings, and follow the QRH steps to isolate the fault and maintain safe flight. The other options don’t fit because simply rechecking later ignores the immediate risk, hydraulic failures are not noncritical, and hydraulic issues involve more than cabin pressurization.