What type of door is the bulk compartment door classified as?

The bulk compartment door on the A320 is classified as a plug type door. This design is characterized by its ability to create a seal when the cabin pressure increases. As the cabin pressure builds during flight, the door is pushed more firmly against its frame, enhancing its sealing capability and preventing any potential leakage.

Plug type doors are typically used in aircraft as they provide a high level of safety due to their structural characteristics. They are designed to fit into a recess in the fuselage, ensuring that the door cannot open while the aircraft is pressurized. This sealing effectiveness is crucial for maintaining cabin pressure and ensuring the safety of passengers and crew during flight. Understanding this classification helps in recognizing the operational and safety features of the aircraft's design, as well as the engineering principles that govern door operation in pressurized environments.