How many PCUs power the rudder?

How many PCUs power the rudder?

• A. 2
• B. 3
• C. 4
• D. 1

Answer: (B)

Redundancy in power for the rudder ensures you retain control even if a component fails. The rudder’s hydraulic power comes from multiple PCUs, and in the CRJ‑550 there are three PCUs dedicated to the rudder. This three‑unit arrangement provides independent power paths to the rudder actuators, so if one PCU or its feed path fails, the remaining PCUs can still move the rudder and preserve directional control. This level of redundancy is essential for safe handling during high‑demand phases of flight, such as takeoff and go‑around, which is why three PCUs power the rudder.

Redundancy in power for the rudder ensures you retain control even if a component fails. The rudder’s hydraulic power comes from multiple PCUs, and in the CRJ‑550 there are three PCUs dedicated to the rudder. This three‑unit arrangement provides independent power paths to the rudder actuators, so if one PCU or its feed path fails, the remaining PCUs can still move the rudder and preserve directional control. This level of redundancy is essential for safe handling during high‑demand phases of flight, such as takeoff and go‑around, which is why three PCUs power the rudder.