Which hydraulic system powers the landing gear?

• A. System 1
• B. System 2
• C. System 3
• D. System 4

Answer: (C)

Landing gear is moved by hydraulic actuators, so it needs a reliable hydraulic pressure source. On many jets, the hydraulic system architecture is split into multiple independent circuits. To ensure the gear can extend or retract even if other systems fail, the gear is driven by a dedicated hydraulic system. In this aircraft’s configuration, that dedicated supply is System 3, whose pump and lines feed the landing gear actuators and doors. When System 3 provides pressure, the gear can be extended or retracted as needed, which is why this system is the correct answer.