How many pumps and what type are used by the Standby hydraulic system?

How many pumps and what type are used by the Standby hydraulic system?

• A. Two electric pumps and one hydraulic pump.
• B. One electric pump.
• C. One hydraulic pump and one electric pump.
• D. Two hydraulic pumps.

Answer: (B)

Standby hydraulic systems are designed to provide limited hydraulic power for essential controls even when the main hydraulic system is unavailable. They accomplish this with a single electric motor–driven pump, powered by the aircraft’s electrical system, often backed by an accumulator to hold pressure for immediate use. This setup keeps the standby system independent from engine-driven or main electric pumps and avoids extra redundancy that isn’t required for emergency use. Because the goal is to supply just enough pressure for critical actuators, one electric pump is sufficient, rather than multiple pumps or a combination of pump types.

Standby hydraulic systems are designed to provide limited hydraulic power for essential controls even when the main hydraulic system is unavailable. They accomplish this with a single electric motor–driven pump, powered by the aircraft’s electrical system, often backed by an accumulator to hold pressure for immediate use. This setup keeps the standby system independent from engine-driven or main electric pumps and avoids extra redundancy that isn’t required for emergency use. Because the goal is to supply just enough pressure for critical actuators, one electric pump is sufficient, rather than multiple pumps or a combination of pump types.