(1) Purpose. The water wash unit is designed to
dispense water and cleaning compound. It contains
automatic temperature and pressure controls which
maintain a constant output of a heated solution at the
(2) Principle of Operation. The universal wash unit
operates on either 115 volts ac, 50-400 Hz, single phase
or 28 volts dc. The wash unit utilizes a power supply,
motor driven pump, spray nozzle, strainer/filter and
wand. An external cleaning solution supply is connected
to the wash unit by the strainer. The motor driven pump
will deliver approximately 2.5 gallons of cleaning
solution per minute at 30 psig through the wand and
nozzle when the wash unit is set to the wash
(3) Safety Practices and Procedures. The following
special precautions should be observed when using the
universal wash unit.
· Keep the cleaning compound away from
· Do not aim the pressurized water at
(4) Operating Procedures. The following general
procedures pertain to the operation of the universal
(a) Position the wash unit at the aircraft.
(b) Connect the strainer unit to the intake
(c) Connect the wand and nozzle spray to the
output (discharge) hose or connect the discharge quick
(d) Insert the strainer unit into a container of
water or cleaning solution.
(e) Press the start or remote start switch;
observe the pressure gage. It should immediately
indicate an increase in pressure.
(f) After the pressure reaches approximately
10 psig, release the start switch. The unit should
continue to operate.
(g) The unit will deliver approximately 2.5
gallons per minute at 30 psig.
(h) Press the stop or remote switch to stop
the unit from operating.
(5) Inspection. General operator inspections for the
wash unit are contained in the following
paragraph. Detailed inspection requirements are in the
applicable maintenance manual.
(a) Inspect power cable and connectors for
bent or broken connector pins, damaged connector
sockets, frayed or cracked insulation and bent or loose
(b) Inspect suction and discharge hoses for
damaged connectors, and cut hose surfaces.
(c) Examine the wand for damaged pipe
surface, damaged connectors and connector threads.
f. Portable Power Supply. The portable power
supply, shown in figure 9-23, is commonly called an
inverter. The unit produces ac power output from dc
power input and is approximately 12 inches long, 8 1/2
inches wide, and 4 1/4 inches high. It functions in a
temperature range of -65 to +1 60F (-54 to +7C).
(1) Purpose. The inverter is designed to convert 28
vdc to 115 vac, 400 Hz, sine wave power at 39 amps.
Figure 9-23. Portable Power Supply