|Quoting B777UA (Thread starter):|
if the Emergency Slides deploy by an Armed exit being opened, How do they replace them? do they have to get all new ones, or do they deflate the current ones and reuse them?
They do both. Speaking only of A320s (other airplanes will be similar), the slides are mounted on a packboard, which is then bolted to the door. When the slide is armed, the slide's girt bar engages in the floor fittings (which you can see at the threshold of the door, at each corner). When the door is opened with the slide armed, a cable fires the nitrogen bottle that's also mounted on the packboard. The slide drops out and inflates, usually in five or six seconds. The packboard, slide cover, bag, and electrical connections stay with the door, but the slide is attached only to the floor fittings.
To remove the slide, you first deflate it using a large flapper valve mounted on the side of the slide. You then disconnect the electrical connections, and unhook the girt bar from the floor fittings. The packboard is removed by undoing the two bolts at the top of the packboard, and lifting it off the lower hooks.
The slide and its packboard are then rolled up and put into a container for shipment to a repacking facility. The procedure to repack the slide is dozens of pages long. I've never done it, but I have rejected slides that weren't packed properly.
The primary function of the design engineer is to make things difficult for the manufacturer and impossible for the AME.