What normally powers the cargo doors?

The cargo doors on the A320 are typically powered by the yellow electric pump. This pump operates the hydraulic systems that facilitate the opening and closing of the cargo doors. The yellow hydraulic system is primarily tasked with operating components associated with the landing gear, cargo doors, and certain flight controls, providing the necessary force to ensure that the doors can be securely and effectively operated.

The yellow electric pump is specifically designed to supplement the power supply to the hydraulic system, ensuring that there is adequate hydraulic pressure available for door operations, even when the engines are not running or in specific operational scenarios. This is critical for safety and reliability in cargo loading and unloading situations.

Other hydraulic systems and pumps serve different purposes, such as the blue electric pump, which is mainly associated with other aircraft functions. Each pump is designated for specific tasks, ensuring that the aircraft operates efficiently and safely. The selected answer reflects the accurate standards in hydraulic systems on the A320.