Cessna 152 - Page 129

CESSNA
MODEL 152
SECTION7
AIRPLANE & SYSTEMS DESCRIPTIONS
white lighting is provided. In the center position, the map light is turned
off. Light intensity of the red light is controlled by the PANEL LT rheostat
control knob.
The most probable cause of a light failure is a burned out bulb;
however, in the event any of the lighting systems fail to illuminate when
turned on, check the appropriate circu¼t breaker. If the circuit breaker has
opened (white button popped out), and there is no obvious indication of a
short circuit (smoke or odor), turn off the light switch of the affected lights,
reset the breaker, and turn the switch on again. If the breaker opens again,
do not reset it.
CABIN HEATING, VENTILATING AND
DEFROSTING SYSTEM
The temperature and volume of airflow into the cabin can be regulated
by manipulation of the push-pull CABIN HT and CABIN AIR control
knobs (see figure 7-8).
Heated fresh air and outside air are blended in a cabin manifold just aft
of the firewall by adjustment of the heat and air controls; this air is then
vented into the ca.bin from outlets in the cabin manifold near the pilot's and
passenger's feet. Windshie.ld defrost air is also supplied by a duct leading
from the manifold.
For ca.bin ventilation, pull the CABIN AIR knob out. To raise the air
temperature, pull the CABIN HT knob out approximately 1/ 4 to 1/ 2 inch
for a small amount of cabin heat. Additional heat is available by pulling
the knob out farther; maximum heat is available with the CABIN HT knob
pulled out and the CABIN AIR knob pushed full in. When no heat is desired
in the cabin, the CABIN HT knob is pushed full in.
Additional ventilation air may be obtained by opening the adjustable
ventilators near the upper left and right corners of the windshield.
PITOT-STATIC SYSTEM AND INSTRUMENTS
The pitot-static system supplies ram air pressure to the airspeed
indicator and static pressure to the airspeed indicator, rate-of-climb
indicator and altimeter. The system is composed of either an unheated or
heated pi tot tube mounted on the lower surface of the left wing, an external
static port on the lower left side of the forward fuselage, and the associated
plumbing necessary to connect the instruments to the sources.
1 July 1978 7-27