@@rofilmproduktion yeah, if you look up "abandoned british airways training facility" you get alot of videos on the training facility you have been to.
These doors must be easy to open because they're required to be used extremely rapidly in an emergency evacuation. A door cannot be opened in the air. Did you notice how the door opens inwards and not outwards? This is to stop it ever opening in flight. The cabin is pressured so highly that the inward opening door is being forced into the frame at a rate of approx 10,000lbs per square inch (703kg per cm²) strong indeed! Not a chance it will open. It's never happened yet!
