Hi folks !!!

I have always wondered how the A320 passenger doors locking mechanism works. Though they are not authentic plug type doors (the door being larger than the door frame and opening inside rather outside), they do have their mechanism where they lock into the door frame tightly as the differential pressure helps to plug the door into its frame. I did browse the FCOMs, the AMM trying to understand how they lock in place and I kind of have a vague idea about the parts(the stop fittings, upper guide,lower guide,roller, locking shaft, locking hook etc).I would really appreciate it if someone could throw light on the exact purposes of each of these parts, how the mechanism works and how they help in securing the door to the fuselage.

I would also appreciate if you kind folks can share any photos/video links/animations that help better understand how the A320 door is secured tight in its place.

Thanks in advance.

The door is sprung loaded upwards in the hinge. There are about 8 lugs each side in the fuselage frame on both sides. There are corresponding metal plates on the door. When you close the door, the metal plates are above the lugs. When you secure the door with the handle, the door is lowered so the metal plates go behind the lugs.

The lugs and plates take all that pressurised load. Scary!

A 320 door

One frame lug is visible by “a” in photo by alamy.
Door metal plates are blue.

Nice, concise explanation.

The OP will find lots of videos on YouTube of the opening/closing sequence.