Rigging The Heater Controls; Overheat Thermostat; Cleaning Heater Spark Plug; Electrode - Beechcraft TRAVEL AIR 95 Shop Manual

fuse can not be replaced
in flight. evidence of cracked or broken
porcelain, arcing or
carbon
tracks.
If cracks are found in
the
porcelain,
the
plug should
be discarded
without further
exami-
RIGGING THE
HEATER CONTROLS nation. Arcing or carbon
tracks
may be caused by
shorting
of
the
plug or by dirt on
the
spring
con-
The cabin air
control on
the
far
left hand side of
the
nector.
In either case
the
fault should
be corrected
subpanel
controls
the
iris valve and
the
heater
safety
before
installing
the
plug in service
or using a new
switch. Place
the
iris valve
actuator as far
to the
plug.
right (facing
forward)
as possible.
With
the
"CABIN
AIR" control
pushed
in,
attach the
control
wire
to
d.
Wipe out
the
inside of
the
heater with a clean
the
iris
valve actuator arm. The safety switch is cloth dampened with solvent,
to
remove any grease
positioned
on
the
underside
of
the
heater
shelf in or carbon deposits.
adjustable
slots.
Pull
the
"CABIN AIR" control
to
the
half-on
position
and set
the
micro safety switch e. Clean
the
spark plug by sand blasting.
arm against
the
guide on
the
control cable
in
the
actuated position, secure
the
micro switch in
this
NOTE
position.
Cover
the
spark plug hole with a stopper
or
When disconnecting
the
iris valve control
for adjust-
cap
to
prevent dirt
or sand from
lodging
ment purposes,
position
the
control in either
the there
during
the
cleaning.
full-open or
full-closed
position, so
that
it may be
reinstalled without disturbing
the
adjustment
of
the
safety switch.
ELECTRODE
The heater ductstat control located
at
the
far right
of
the
left hand subpanel
controls
the
heater
thermo-
stat.
With
the
"CABIN HEAT" control pushed in and
'¯
the
lug on
the
ductstat pushed
to
the
far right
(facing
..
forward), push
the
control wire
thru the
lug
and
tighten the
screw. Make
sure
the
guide
lug on
the
ductstat switch is in
the
straight upright position
before
securing
the
control
wire on
aircraft prior
CERAMIC
to
Serial TD-453, and in
the
straight downward
AREA
position on airplane Serial
TD-453
and after. SPARK
PLUG
INSPECT
FOR
WELL
CARBON HERE
OVERHEAT THERMOSTAT
Figure
3-12.
Aircraft
Heater
Spark
Plug
The overheat
thermostat
is controlled
by an adjust-
ing screw on
the
bottom of
the thermostat. A letter
"H" with an arrow
through
it
on
the
head of
the
HEATER SPARK PLUG
GAP
switch indicates
the
direction
the
sleeve be
turned
to
increase
the temperature
setting.
One
turn
will
Heater
spark plug gap should
be set from
0.312
to
change
the temperature
setting
approximately
125
0.250 inches.
The
gap is
determined by measuring
degrees
Fahrenheit,
the
distance
between
the
spark
plug
electrode and
the
ground
electrode. The gap may be adjusted by
The
overheat
thermostat
is set at
the
factory
to
adding or removing shims
under
the
electrodes until
operate at 300 degrees
Fahrenheit and
ordinarily
the desired
distance is obtained.
will not need
to
be
adjusted.
WARNING
REMOVING
AND
INSTALLING
THE CABIN
HEATER
IGNITION
UNIT
Never set
the thermostat for
temperatures
above
300 degrees
Fahrenheit. The heater
To remove
the
heater
ignition
unit,
disconnect
the
is not designed for higher
temperatures
wiring at
the
electrical
plug,
disconnect
the
ignition
and fire may result.
lead,
remove
the
ignition unit attaching
screws
and
remove
the
unit. Reinstall
the
ignition unit by
reversing
the
removal procedure.
CLEANING
HEATER SPARK
PLUG
a.
Remove
the
nose
cone,
to
gain access
to
heater.
HEATER IGNITOR POINTS
Disconnect
the
high
tension
lead from
the
spark
plug.
Two sets of
heater ignition
points are
installed in
the vibrator
of
the
heater
ignition
unit. The primary
b. Remove
the
spark
plug using
a
deep socket.
set of ignitor
points has
a service
life of 1000 hours,
(heater operation).
At
this time,
on
Aircraft
TD-534
c. Before
cleaning,
examine
the
spark
plug
for thru
TD-707,
the
alternate
set of points should
be
3-24