What is missing here?

[Bruce D]

What part is missing here to complete the drainage system? I have done a quick search for this part but I'm not sure what I'm looking for. Thanks Bruce

[HiJoeSilver]

Took a second to figure this image out, but that's the hole in the rear frame protrusion that you have the waste drain go out. You need a shout piece of 3" abs pipe and one of these (http://www.etrailer.com/Plumbing/Val...FQqKaQodMJMGrw) 3" pipe to hose terminations. You'll have to cut a short piece of abs pipe to fit between the part there and the termination piece. That is if I'm correct and it looks like the pipe end we're seeing is a female junction. If it's not you'll need a 3" abs coupler to join the ends of the 2 pieces. Clean that dirty pipe joint well before gluing with abs cement.
You can get all of this on Amazon or at a rv supply place. Depending on where you live the hardware store may have abs pipe and fittings, except the terminal piece.

[A W Warn]

I think the coupling visible in the photo would have originally been a Calder coupling, a rubber coupling. They were really short. I think that type is no longer available. If you need this part, a similar alternative would be a 3"x3" Fernco coupling. It is longer than the original, but will work. From the coupling you will need to extend that pipe about 2'" to 3" beyond the metal then add the part HiJoSilver suggested.

Originally there would have been an escutcheon (trim ring) that fit tight onto the pipe and covered the perimeter of the hole in the metal. I think these trims are no longer available. As an alternate, a piece of heavy rubber sheet (like a truck bed mat or mud flap) could be cut as needed. Or, maybe a 3"x4" Fernco coupling could be trimmed short to create a cone shaped trim. Either of these would need to be slid over the pipe before installing the sewer termination.

You can see that escutcheon here at post #5 (but the valve is an add on, not original):
http://www.airforums.com/forums/f44/...gy-122464.html

[Bruce D]

Thanks Joe! Exactly what I needed. Just ordered it and a cap. What you see is a fernco connector. I'll just lossen the band and install the new piece. I hope to get the old girl ready to go camping soon.

[HiJoeSilver]

Amazed AWWarn could tell that was a rubber coupling. If it's really old you may want to replace the old rubber fitting if it's showing its age.
You can jerry rig a new trim for the penetration with a piece of the rubber boot from a 3" roof vent stack penetration seal. It's mostly cosmetic. (https://www.zoro.com/oatey-roof-flas...A&gclsrc=aw.ds) if you cut one of these at the lower rubber edge and slide it over the pipe before sliding it through the hole you'll get a nice trim ring that will press against the frame for a bit of a seal. They're cheap and readily available.

[Streamracer]

You might try Sonny at Camper Repair in Montevallo, Al 205-665-2531. He sels new and used parts. He is an Airstream parts dealer.

[Bruce D]

Thanks Streamracer, I am going to get a couple of window lift arms and a KT entry lock set(ouch) from him next week. Keep him in your prayers. He is having some health issues.