Abstract: A lavatory system suitable for use on a commercial passenger aircraft includes at least one toilet bowl for receiving waste and a waste-holding tank in fluid communication with said toilet bowl for receiving waste from said toilet bowl. The waste-holding tank is kept at a pressure less than the ambient pressure surrounding the toilet bowl so that waste from the toilet bowl is drawn to the tank by the difference in pressure. A flush valve is provided in the drain line between the toilet bowl and the waste-holding tank and is selectively operable to pass the toilet bowl contents into the waste-holding tank. Water from the potable water supply system is provided to the toilet bowl to wash the sides of the toilet bowl and to assist in moving the waste material to the drain line. A water inlet valve is provided to selectively control the introduction of water into the toilet bowl and preferably the water inlet valve and flush valve are operated in a timed sequence by actuation of a single flushing switch.

Abstract: A drainage apparatus for an aircraft lavatory system includes a waste holding tank that receives waste from the individual toilet units. The waste holding tank has a pressurization port and a waste drain opening formed in an upper portion thereof. A blower is coupled to the pressurization port to force air into the tank to pressurize it, thereby forcing waste out of the tank through the waste drain opening. The waste travels through an internal waste drain conduit having a first end located at the bottom of the tank below the level of the waste and a second end coupled to the waste drain opening. Preferably, a flow control device is interposed in fluid communication between the blower and the pressurization port and is operable to direct the flow of air from the blower either into the tank for pressurization or out of the tank to create a partial vacuum within the tank to aid in vacuum flush of the toilet units. An auxiliary pressurization source is also provided in the event of blower failure.

Abstract: A single water closet or toilet fixture for dual functional use as either a western style fixture wherein the user is in the sitting position and normally facing forward, or an eastern style fixture wherein the user is in the squatting position and facing either in the forward direction or the aft direction depending on the embodiment utilized. An external footrest is provided on each side of the fixture for supporting the user in the squatting position. A movable toilet seat when folded down onto the lower bowl portion of the toilet fixture is proportioned for use in the sitting position; and when the toilet seat is raised to an upright position, a fore and aft elongated receptical or bowl portion is exposed which is relatively narrow in width for straddling and is proportioned for use in the squatting position. Also, formed integral with the bowl portion of the fixture, is a urine spray shield which nestles under the contoured toilet seat and is functional in both the sitting and the squatting positions.

Abstract: A vacuum flush waste diposal system for aircraft; wherein the required vacuum is acquired at altitude through the differential pressure between the aircraft cabin pressure and the ambient pressure above approximately 15,000 feet. When the aircraft is below this altitude or on the ground, the vacuum is provided by a blower. For flushing the toilet bowl, a timing device is initially actuated and functions: to introduce a recirculated flush fluid into a flush ring in the upper portion of the toilet bowl; and to open a drain in the lower portion of the toilet bowl, leading to the vacuum waste line; whereby, the waste and flush water are rapidly propelled through the waste line towards a centrally located holding tank, by the differential pressure acting upon it. Once in the holding tank, the waste fluid is filtered out for further use as the recirculated flush fluid.