AIRLINX is working on an affordable solution for assuring that lavatory service trucks incorporate a “closed” and sanitary solution for lavatory vehicle drain systems. AIRLINX will soon offer lavatory drain assemblies that can be adapted to lavatory truck drain outlets. It will incorporate a 4 inch drain nipple/flange that will accept a drain coupling (“Wye” drain or straight) for truck waste disposal. Internally the nipple assembly will be grooved to accept a lavatory drain plug (AIRLINX part number V4259J064S20) assuring that the line will be completely sealed from waste fluid. The drain nipple will accept a ¼ turn-to-lock sealing cap cover (AIRLINX part number V2651J126A00 / V2651J075A00 / V2651J154A00) secured to the assembly either by a chain or lanyard. AIRLINX will offer connection to the lavatory service truck by either a 4 inch hose barb or a 4 inch National Pipe Thread (NPT) connection.