How many PCUs power the Ailerons?

How many PCUs power the Ailerons?

• A. 2 PCUs total
• B. 3 PCUs total
• C. 4 PCUs total
• D. 6 PCUs total

Answer: (C)

Power Control Units regulate hydraulic pressure to move the aileron actuators. On the CRJ-550, there are two aileron surfaces on each wing—an inboard and an outboard. Each surface has its own PCU, providing independent control and redundancy. That means there are four PCUs powering the ailerons in total. This setup ensures that roll control remains available even if one PCU or hydraulic path is in trouble.

Power Control Units regulate hydraulic pressure to move the aileron actuators. On the CRJ-550, there are two aileron surfaces on each wing—an inboard and an outboard. Each surface has its own PCU, providing independent control and redundancy. That means there are four PCUs powering the ailerons in total. This setup ensures that roll control remains available even if one PCU or hydraulic path is in trouble.