Which condition will illuminate the RAT and EMER GEN red FAULT light?

Which condition will illuminate the RAT and EMER GEN red FAULT light?

• A. EMER GEN not providing power with both AC BUS 1 and AC BUS 2 depowered
• B. One AC BUS is depowered
• C. RAT deployed and GCU energized
• D. Hydraulic leak in Green system

Answer: (D)

The emergency power path on the A320 relies on the RAT to drive the emergency generator and supply essential power when normal AC sources are lost. If the Green hydraulic system has a leak, the RAT can’t be powered or driven properly, so it cannot generate emergency electrical power. That loss of RAT function means the emergency generator isn’t providing power and the fault is detected, lighting both red indicators. In other scenarios, the emergency path either remains capable of producing power or does not produce the same simultaneous fault indication, so they don’t illuminate together.

The emergency power path on the A320 relies on the RAT to drive the emergency generator and supply essential power when normal AC sources are lost. If the Green hydraulic system has a leak, the RAT can’t be powered or driven properly, so it cannot generate emergency electrical power. That loss of RAT function means the emergency generator isn’t providing power and the fault is detected, lighting both red indicators. In other scenarios, the emergency path either remains capable of producing power or does not produce the same simultaneous fault indication, so they don’t illuminate together.