Plain English Meaning

Something has gone wrong with the system that uses pressurized fluid to move parts of the airplane like the landing gear, brakes, or flaps. Depending on the failure, those parts may work poorly or not at all.

Full Definition

Failures or abnormal conditions in an airplane's hydraulic system, which uses pressurized fluid to operate components such as landing gear, flaps, brakes, and flight controls. Malfunctions can include loss of fluid, loss of pump pressure, broken lines, or contamination, and may result in partial or complete loss of the systems the hydraulics power.

Context Anchor

Encountered during emergency and , especially when planning an or with possible , , , or problems.