Effective: 03/26/2010; Dispersal Systems; General Description; Hopper - THRUSH S2R – G10 Maintenance Manual

AIRCRAFT MAINTENANCE MANUAL

DISPERSAL SYSTEMS

GENERAL DESCRIPTION

A reinforced fiberglass hopper is the
principal part of both the solid and spray
units. The hopper top forms the cowling
from the cockpit forward to the firewall.
The hopper gate box is designed to be
liquid as well as dust tight. Emergency
jettison controls permit the entire liquid
load to be dumped in approximately 7
seconds for the 400 gal. Hoppers.
The dispersal system has been designed
to handle a wide range of dispersal
equipment, and to allow for a quick, easy
changeover from one type of equipment
to another. All dispersal plumbing is
externally mounted and equipped with
quick-disconnects to allow for ease of
maintenance and
streamlined aluminum extrusion spray
booms are located below the wing
trailing edge and utilize the downwash
from the wing to increase penetration
(See Figure 9-4). The booms are fitted
with spraying system diaphragm type
nozzles and normally will use 35 nozzles
for low volume output and 70 nozzles for
high volume output.
spray booms have large end plugs that
can be removed to aid in flushing the
system.
The spray pump is located under the
fuselage between the main landing gear
struts. A three-way suck-back spray
valve located at the left, underside of the
fuselage, controls the spray pressure
and flow. The valve is actuated from the
cockpit to obtain the desired operating
pressures for various spray applications.
Spray pressure is indicated by a gauge
mounted on the left boom and is
controlled by a vernier adjustment on the
liquid spray-operating handle. The spray
pump is a wind-driven fan type.
9-2
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THRUSH AIRCRAFT, INC – MODEL S2R-G10
cleaning. The
In addition, the

HOPPER

Ref. Figure 9-1

HOPPER CARE

Regardless of the materials used in the
construction or coating of the hopper, it
should be thoroughly washed after each
day's work. Use cold, clean water and any
domestic detergent. Inspect the interior of
the hopper daily for evidence of chemical
attack, such as surface roughness or
deterioration of the resin. Look for cracks
that may have started in the areas of highest
stress, such as attach points and stiffener
center portions. Repairs should be made at
the beginning of the problem, rather than
after it has progressed to a serious degree.
* NOTE *
After washing, it is very important
that the door and gate be left open
for good ventilation and complete
drying. It is good practice to rinse
the hopper with cold water after use
with chemicals, even if the idle
period ahead is going to be only a
few hours.

HOPPER REPAIR

Ref. Figure 9-2
Hopper repairs should be accomplished as
follows:
A. Fiberglass surfaces must be clean, dry
and free of oil, wax or other foreign
matter. If chemical erosion is evident,
sand rough areas and wash with any
good domestic detergent.
clean water. Sand all surfaces that are
to receive a polyester coating.
Ashland Specialty Chemical Company's
7241 T15 AROPOL™ polyester resin or
equivalent for the hopper repair.
Rinse with
Use

Effective: 03/26/2010