The emergency hydraulic system _______________________________.

• A. Has separate and independent hydraulic lines that ensure gear/flap operation if primary system fails
• B. Uses an engine-driven pump to produce pressure
• C. Shares the hydraulic lines leading to the actuators with the primary hydraulic system
• D. Provides 3000 +/- 120 psi to raise the landing gear and flaps

Answer: (C)

The key idea is that the emergency hydraulic system taps into the same feed lines that go to the actuators as the primary system. When the main system is unavailable, a backup source still pressurizes those shared lines so essential components like landing gear and flaps can be moved. This avoids duplicating a separate set of pipes to the actuators and relies on a backup pump or power source to push fluid through the same paths.

Choosing a completely separate, independent set of lines would imply a different circuit for the actuators, which isn’t how this system is described. The exact pressure delivered by the emergency system isn’t the defining feature and can vary by aircraft, so citing a fixed value isn’t appropriate.