Actually, it's cool how the tailcone exit works on the DC9 aircraft. First, on some of the earlier DC9s, there is a plug-type hatch that you can open and crawl through to get out the back of the plane. It is much scarier and probably more dangerous, and Douglas realized that and made a modification to its newer DC9 series planes which was more comfortable and definitely safer.
The MD-80 series has two ways to get out the tailcone, but cannot be realistically used simultaneously. In a minor accident, the stairs are used , which means the door is disarmed and you open it up and walk straight out. In an emergency where the slide is necessary, the door must first be in the armed position. When the handle is turned, it releases a catwalk from the ceiling which slams down over the stairs, revealing an uphill walkway to the tailcone. You follow the arrows to a red handle, and pull back on it. This releases the tailcone to the side of the escape path and blows the slide. The pack itself is placed on top of the girt bar, but a pin is attached to the removable tailcone, which, when released, should open the pneumatic inflation canisters and fill the slide. If not, it also has the manual inflate handle just like every other slide. The slide pops out, and pax can evacuate. Next time you are coming out the back of a DC9, check out the ceiling. It's pretty cool.
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Photo © Peter Polakos
The slide has been removed from the 80 in this picture, but you can see the tailcone has been shot off in the accident.