may also remove the plug from spray boom ends to
speed the flushing and draining.
(5) Clean and decontaminate the helicopter,
If desired for cleaning operation, remove
spray system, and liquid loading system as required.
nylon plugs from end of spray booms
(6) Leave both the control valve (25) and
prior to flushing operations to speed up
bypass valve (24) in the middle (unlocked) position when
the cleaning and flushing process.
the system is not in use.
(4) A second but less thorough method of
cleaning and flushing the spray system is to dump
cleaning fluid by gravity feed while aircraft is on ground.
Place valve control lever (27, fig. 12) in VALVE OPEN
Section IV. OPERATION UNDER UNUSUAL CONDITIONS
sprayer system in cold weather may require warming the
spray fluid prior to spraying operations. To preheat the
Use of the insecticide sprayer system under unusual
fluid, place handle of bypass valve (24, fig. 12) in TANK
weather conditions depends much on the capabilities
OPEN position to direct fluid back into tank. Place valve
and limitations of the aircraft with which it is used. Refer
control lever (27) in CLOSED position to direct fluid to
to the documents which apply to UH1B and UH1D
the bypass valve. Place the pump brake lever (29) in
helicopters for special procedures.
BRAKE OFF position to permit fluid to circulate for
a. General. To insure proper operation, keep
c. Operation in extreme heat. When using the
the equipment clean and operate and maintain it as
liquid loading system pump in extreme heat, observe the
instructed in this manual. The following additional steps
are provided for conditions under which the equipment
(1) Check the cooling fins on the engine
may be expected to operate:
cylinder often to be sure they are clean and not
b. Operation in freezing weather. Using the
system in freezing weather poses the problem of liquids
(2) If possible, provide shade to protect
freezing in the pumps, containers, tank, lines, spray
the unit from the direct rays of the sun.
booms, and nozzles. Generally, operations will not be
d. Operation in dusty areas.
carried out when daytime temperatures are at such
spraying system in dusty areas will require careful
However, overnight freezing may be
inspection and cleaning procedures. Use the following
encountered in areas where the equipment is required to
as a guide (refer also to preventive maintenance checks
operate. It is best to allow the equipment to thaw out
and services, paragraph 34):
naturally, without applying external heat. Thoroughly
(1) Oily surfaces attract dust quite readily.
draining the equipment and covering overnight will
Therefore, since the insecticide spray in itself
reduce the effects of short term freezing weather. The
may be an oil-base fluid, the spray nozzles and other
following steps will help protect the liquid loading pump
parts must be inspected and cleaned often.
engine from freezing.
(2) Keep outer portions of all equipment clean
(1) Keep fuel tank of liquid loading pump
to prevent dirt buildup.
full at all times to prevent moisture buildup. Keep fuel
(3) Inspect and repair all leaks and loose
tank cap securely closed except just before starting,
connections promptly when leakage is noted.
when it is loosened to break a possible vacuum.
(4) Inspect and clean filters and strainers often.
(2) Use winter grade gasoline in fuel
The liquid loading engine air filter may require weekly or
mixture for easier starting.
even daily cleaning.
(3) Before starting engine, check to see if
pump is frozen. Pull starter cord just enough to see if
Never run engine with a clogged air
crankshaft will turn freely. If pump impeller is frozen fast,
heat the pump slowly, until the ice melts.
filter or with air filter removed.
(4) Start the engine as described in
(5) Always use dust caps provided with
paragraph 25, step b. You may need to crank the engine
liquid loading system quick disconnect couplings. Never
a few extra times to start. Use extra care to insure that
drop hoses in dirt.
the engine warms up completely before pumping fluid.
(6) Keep spray fluid, gasoline, and oil cans
(5) Operation in cold weather. Use of the
covered to prevent dirt getting into these fluids.
(7) Use only clean gasoline and oil in
pump engine to prevent clogging of fuel filter wick.
e. Operation in salt water areas.
(1) Salt water and sea air are very
corrosive. If the equipment is used in a salt water area,