Piper SENECA III - Page 294

SECTION 9
.
PIPER
AIRCRAFT CORPORATION
SUPPLEMENT
6
PA-34-220T,
SENÈCA
III
For
Dight
into
known
icing
conditions,
a
complete ice protection
system
(Figure 9-1)
is
required
on
the Seneca
Ill.
The
complete
ice
protection
system
consists of
the
following
com-
ponents:
pneumatic
wing
and
empennage
boots,
wing
ice
detection light,
electrothermal propeller
deice pads,
electric
windshield
panel, heated
lift
detectors.
and
heated
pitot
head.
A
single
system
or any
combination
of
systems
may
be
installed. However,
the
warning
placard
specified
in Section
2
of
this
supplement
is
required.
Such
a
placard
is
also required
if
any
system
is
inoperative.
The
pneumatic
wing
and
empennage
boots
are
installed
on
the
leading
edges
of
the
wings,
the
vertical stabilizer and the
horizontal
stabilator.
During
normal
operation,
when
the
surface
deicer
system
is off,
the engine-
driven
pneumatic
pumps
apply
a
constant
suction
to
the
deicer
boots
to
provide
smooth,
streamlined
leading edges.
Deicer boots
are
inflated by
a
momentary
ON
type
SURFACE
DE-ICE
switch (Figure
9-3) located
on
the
instrument panel
to
the right
of
the
control
quadrant.
Actuation of the
surface deice
switch activates
a
system
cycle
timer
that
energizes
the
pneumatic
pressure
control
valves
until
the
system
pressure
reaches
17
psi
or
until
6
seconds
is reached.
The
boot
solenoid
valves
are
activated and
air
pressure
is
released
to
the boots,
inflating-all
surface deicers
on
the
airplane.
A
green
indicator light illuminates
when
the
wing-tail
deicer
surface boots
are
inflated
above
8
psi,
The
light also
incorporates
a
press-to-test
and
turn-to-dim
feature. When
the
cycle
is
complete,
the
deicer
solenoid
valves
permit automatic
overboard
exhaustion
of
pressurized
air.
Suction
is
then
reapplied
to
the deicer
boots.
The
deicer
boots
do
not
inflate during the
press-to-test
cycle.
Circuit
protection
for the
surface
deicer
system
is
provided by
a
wing tail
deice.
WT
DE-ICE,
circuit breaker
located
on
the circuit breaker panel.
Wing
icing
conditions
may
be
detected
during
night
flight.
by
use
of
an
ice
detection
light
installed
in the outboard
side of the left engine
nacelle.
The
light is
controlled
by
a
WlNG
ICE LIGHT
switch
(
Figure
9-3) located
on
the instrument
panel
to
the
right of the
surface deice
switch.
A
wing
ice
light,
W/lCE.
circuit breaker
located
in
the
circuit breaker
panel provides
circuit
protection,
REPORT:
VB-1110
ISSUED: JANUARY 8, 1981
9-46,
2
of
10
REVISED: AUGUST
17,
1981