Which pump can supply hydraulic pressure to the tail rotor servo's second stage when the primary pump is failed?

Which pump can supply hydraulic pressure to the tail rotor servo's second stage when the primary pump is failed?

• A. Backup pump
• B. Main #2 pump
• C. APU hydraulic pump
• D. Electrical pump

Answer: (C)

When hydraulic redundancy matters for the tail rotor, you want an independent source that can pressurize the tail rotor servo even if the engines’ pumps are failed. The APU hydraulic pump provides that dedicated emergency supply. It can be brought online to deliver the hydraulic pressure the tail rotor servo’s second stage requires, preserving yaw control when the primary pump isn’t available. The other pumps aren’t the designated emergency source for this specific path. The backup pump serves other hydraulic circuits, the main #2 pump is another engine-driven source used in different conditions, and the electrical pump isn’t the configured source to pressurize the tail rotor servo’s second stage in this scenario.

When hydraulic redundancy matters for the tail rotor, you want an independent source that can pressurize the tail rotor servo even if the engines’ pumps are failed. The APU hydraulic pump provides that dedicated emergency supply. It can be brought online to deliver the hydraulic pressure the tail rotor servo’s second stage requires, preserving yaw control when the primary pump isn’t available.

The other pumps aren’t the designated emergency source for this specific path. The backup pump serves other hydraulic circuits, the main #2 pump is another engine-driven source used in different conditions, and the electrical pump isn’t the configured source to pressurize the tail rotor servo’s second stage in this scenario.