Learning Objective: Recognize motor and
converter assembly components for wind-
shield wiper utility systems.
The windshield wiper system on the S-3 air-
craft is typical of this system and provides visual
clearance for the pilot and copilot in adverse flight
conditions up to speeds of 300 knots. The wind-
shield wiper system consists of a motor assembly,
converter assembly, an arm assembly, a blade
assembly, and an anti-icing and windshield
control panel assembly.
The motor assembly is a three-phase, two-
speed electrically driven motor, which provides
the source of power to the converter assembly.
The converter assembly is a motion converter,
which converts the circular motion of the motor
to the oscillating motion required by the wind-
shield wiper arm.
The arm assembly uses the oscillating motion
of the converter assembly to impart a sweeping
motion to the windshield wiper blade assembly.
The blade assembly consists of a spring-loaded
holder subassembly and a rubber wiper blade. The
blade assembly uses the motion of the arm
assembly to sweep rain from the windshield.
The anti-icing and windshield control panel
provides mounting for bleed-air, wiper, rain repel,
washer, and heat control switches. The windshield
panel consists of a mounting plate, an edge-lighted
panel, six switches, and a wiring harness.
Learning Objective: Recognize reservoir
pump and nozzle assembly components
and capabilities for windshield washer util-
The windshield washer utility system (fig. 1-21)
on the S-3 aircraft is typical of this system and
is located in the unpressurized nose compartment
at the base of the windshield. The washer switch
on the windshield panel, mounted on the overhead
panel, is a two-position switch. When the washer
switch is set to ON, the pump motor is energized
to cause fluid to be sprayed on both windshields.
The spray continues as long as the switch is held
in the ON position. The washer pump supplies
fluid for approximately 6 minutes when the fluid
reservoir is full. A reservoir fillercap dipstick
indicates fluid quantity. Washer fluid consists of
80% isopropyl alcohol and 20% distilled water.
The windshield washer system consists of a
reservoir pump assembly and nozzle assemblies.
RESERVOIR PUMP ASSEMBLY
The reservoir pump assembly provides storage
for a supply of windshield washer fluid and for
mounting of the motor/pump subassembly (with
filter element), the pump housing subassembly,
and the fillercap/dipstick subassembly. The
motor/pump subassembly, which is mounted
submerged in the windshield washer reservoir,
provides a flow of windshield washer fluid in
sufficient quantity and pressure to wash the
When the washer switch on the windshield
panel is set to ON, dc power from the left primary
dc bus is applied to actuate the K57 relay switch
in the left load center. The relay switch, in turn,
applies an ac voltage to the motor/pump
subassembly, which pumps washer fluid out
through the nozzle assembly and on to the
A nozzle assembly is mounted at the base of
each windshield. When the windshield washer
system is in operation, the nozzle assemblies spray
washer fluid onto the windshields.
Learning Objective: Identify functions
and components for rain repellent utility
The rain repellent system discharges fluid onto
the pilots and copilots windshields from a