If both the #1 hydraulic pump and the backup pump have failed, which hydraulic component remains pressurized?

If both the #1 hydraulic pump and the backup pump have failed, which hydraulic component remains pressurized?

• A. Yaw boost servo
• B. Tail rotor servo stage 2
• C. Pilot assist servo
• D. Main rotor servo

Answer: (A)

In the UH-60 hydraulic system, some components can stay pressurized for a while thanks to accumulators that store hydraulic energy. The yaw boost servo has its pressure backed by such an accumulator, so if both the #1 hydraulic pump and the backup pump fail, the yaw boost circuit still remains pressurized for a limited time. This lets the pilot maintain tail rotor authority and some directional control while you deal with the loss of pumps. The other servos—tail rotor servo stage 2, pilot assist servo, and main rotor servo—don’t have pressure held in this way, so they lose hydraulic power when the pumps are out.

In the UH-60 hydraulic system, some components can stay pressurized for a while thanks to accumulators that store hydraulic energy. The yaw boost servo has its pressure backed by such an accumulator, so if both the #1 hydraulic pump and the backup pump fail, the yaw boost circuit still remains pressurized for a limited time. This lets the pilot maintain tail rotor authority and some directional control while you deal with the loss of pumps. The other servos—tail rotor servo stage 2, pilot assist servo, and main rotor servo—don’t have pressure held in this way, so they lose hydraulic power when the pumps are out.