Description; Operation; Trouble Shooting; Removal, Repair And Installation - Cessna 150 Series Service Manual

14-7. DEFROSTER SYSTEM,
mounted in the inboard leading edges of the wings is
ducted to the adjustable ventilators mounted on each
14-8. DESCRIPTION. The defrosting system is cor-
side of the cabin near the upper corners of the wind-
prised of the duct across the aft side of the firewall,
shield. Forward cabin ventilation is provided by a
a defroster outlet, mounted on the left side of the
fresh air scoop door, mounted on the right side of the
cowl deck, immediately aft of the windshield, and
fuselage, just forward of the copilot seat. The scoop
flexible ducting connecting the system.
door is operated by a control in the instrument panel
marked "CABIN AIR. " Fresh air from the scoop door
14-9. OPERATION.
Air from the duct across the
is routed to the duct across the aft side of the firewall,
aft side of the firewall flows through a flexible duct
where it is distributed into the cabin. As long as the
to the defroster outlet. The temperature and volume
"CABIN HT" control is pushed in, no heated air can
of this air is controlled by the settings of the heater
enter the firewall duct; therefore, when the "CABIN
system control
AIR" control is pulled out, only fresh air from the
scoop will flow through the duct into the cabin. As
14-10. TROUBLE SHOOTING.
Since the defrosting
the "CABIN HT" control is gradually pulled out, more
system depends on proper operation of the heating
and more heated air will blend with the fresh air from
system, refer to paragraph 14-5 for trouble shooting
the scoop and be distributed into the cabin. Either
the heating and defrosting systems.
one, or both of the controls may be set at any position
from full open to full closed.
14-11. REMOVAL, REPAIR AND INSTALLATION.
Figure 14-1 may be used as a guide for removal, re-
14-15. TROUBLE SHOOTING. Most of the operational
pair and installation of defrosting system components.
troubles in the ventilating system are caused by stick-
Cut hoses to length and install in the original routing.
ing or binding of the inlet scoop door or its control.
Trim hose winding shorter than the hose to allow
Check filter element in the inlet scoop door. The ele-
clamps to be fitted. A defective defroster outlet must
ment may be removed and cleaned or replaced. Since
be repaired or replaced.
air passing through the filter is emitted into the cabin,
do not use a cleaning solution which would contaminate
14-12. VENTILATING SYSTEM.
cabin air. The filter may be removed to increase air
flow. However, the removal will cause a slight in-
14-13. DESCRIPTION. The ventilating system is crease in noise level.
comprised of an airscoop mounted in the inboard lead-
ing edge of each wing, an adjustable ventilator mounted
14-16. REMOVAL, REPAIR AND INSTALLATION.
on each side of the cabin near the upper corners of
Figure 14-1 may be used as a guide for removal, re-
the windshield, a fresh air scoop door mounted on the pair and installation of ventilating system components.
right side of the fuselage, a control knob on the instru-
A defective ventilator or scoop door must be repaired
ment panel, and flexible ducting connecting the system. or replaced.
Check for proper operation of ventilat-
ing controls after installation or repair.
14-14. OPERATION. Air received from scoops
SHOP NOTES:
14-3/(14-4 blank)