Revision 4 - Cessna 172SPHUSR05 Pilot Operating Handbook

S ECTION 7
&
AIRPLAN E SYSTEMS D ESC R I PTION
I
G l areshield lighting is provided by either a fluorescent l ig ht or a
series of LED lig hts recessed i nto the lower surface of the
glaresh ield . Th is l ig ht is control led by rotating the G LARES H I ELD
L T dim m er, located below the nav i ndicators. Rotating the d i m mer
clockwise i ncreases
cou nterclockwise decrease l ig ht i ntensity.
Pedestal l ig hting consists of a single, hooded light located above
the fuel selector.This l ight is controlled by rotating the PED ESTAL
L T d i m mer, located below the nav i ndicators. Rotating the d i m mer
clockwise increases
counterclockwise decreases light i ntensity.
Panel l ig hting is accomplished using i nd ivid ual lights mounted i n
each i nstru ment and gauge. These l ights are wi red i n paral lel and
are control led by the PAN EL L T dimmer, located below the nav
i ndicators . Rotating the d i m mer clockwise increases light i ntensity,
and rotating the dimmer cou nterclockwise decreases light i ntensity.
I
Pilot control wheel l ig hting is accomplished by use of a rheostat
and l ig ht assembly, located u nderneath the pilot control whee l . The
lig ht provides downward i l l u m i nation from the bottom of the control
wheel to the pilot's lap area. To operate the light, first turn on the
NAV light switch , then adjust the map light i ntensity with the knu rled
rheostat knob. Rotating the d i m mer clockwise increases l ig ht
i ntensity, and rotating the d i m mer cou nterclockwise decreases l ig ht
i ntensity.
In addition to the RAD IO L T d i mmer, l ighting i ntensity for the
avionics displays and the NAV i ndicators (pilot's panel) is controlled
by the annunciator panel test switch . When the switch is i n the BRT
position (earl ier serial n u mber airplanes) or the DAY position (later
serial n u mber ai rplanes) , this lighting may be off regardless of the
RAD I O L T d i m mer position.
Regardless of the l ig ht system in question, the most probable
cause of a light fail u re is a bu rned out bulb. However, i n the event
any of the lighting systems fai l to i l l u m i nate when tu rned on, check
the appropriate circuit breaker. If the circu it breaker has opened,
and there is no obvious i ndication of a short circuit (smoke or odor) ,
turn off the light switch of the affected l ig ht, reset the breaker, and
turn the switch on again . If the breaker opens again , do not reset it.
7-38
lig ht i ntensity,
l ig ht i ntensity,
MODEL 1 72S
and rotating the dimmer
and rotating the dimmer
C ESSNA

Revision 4