Monogram 15900-012 Assembly page 17

3. Operation
A. The operation of the toilet begins with the initiation of the flush cycle. The electric motor of
the motor-pump-filter unit assembly is energized for approximately 10 seconds. Throughout
the flush cycle, flushing fluid is drawn thought the filter by the pump and discharged into the
toilet bowl in a swirling action to wash waste into the tank assembly.
B. Toilet Assemblies must be serviced after each scheduled flight by emptying, flushing, and
recharging the tanks with fluid containing a dye-deodorant-disinfectant-chemical-water
solution. Draining, cleaning and filling of the toilet assemblies is controlled from the aircraft
toilet ground servicing panel. During toilet tank draining and cleaning, the tank drain valve
is opened. The drain valve is a plunger type valve which is spring loaded to the closed
position. A pull force of approximately 35 pounds (15.91 Kg) is required to open the valve.
During tank cleaning and filling, fresh water is pumped into the toilet tank from an aircraft
lavatory servicing vehicle. The water enters the toilet tank through an inlet fitting of the
solenoid valve assembly, before going into the rotating spray nozzle via hose connection to
the pump inlet. The rotating spray nozzle is part of the motor-pump-filter assembly. The
pressurized fluid is jettisoned through spray nozzle openings and cleanses the inside of the
filter basket and tank side walls at same time pre-charge fluid is added. After the cleaning
operation the Liquid Level Transmitter will indicate when the fluid reaches the proper pre-
charge level.
4. Leading Particulars
Electrical Power Rating
Fluid Pump Capacity (Nominal) 10.0+ 1 GPM (37.85+3.79 LPM)
Flushing Cycle (Nominal)
Tank Capacity, Total
Usable Capacity
Priming Precharge
Monogram Sanitation
COMPONENT MAINTENANCE MANUAL
PN 15900-012 Series
Use
Leading Particulars
Toilet Facilities
+28 VDC, 5 AMPS Nom.
10+2 Seconds
7.5 Gal (28.39 Liters)
3.8 Gal (14.38 Liters)
1.6 Gal (6.06 Liters)
Table 1
38-31-07
Page 3/4
Jan 10/95