Cessna SkyHawk SP 172S NAV III 2005 Pilot Operating Handbook page 91

SECTION 3
EMERGENCY PROCEDURES
CESSNA
MODEL 172S NAV III
ATTITUDE AND HEADING REFERENCE SYSTEM
(AHRS) FAILURE
RED X - PFD ATTITUDE INDICATOR
1. ADC/AHRS Circuit Breakers - CHECK IN (ESS BUS and
AVN BUS 1). If open, reset (close) circuit breaker. If circuit
breaker opens again, do not reset.
2. Standby Attitude Indicator - USE FOR AnlTUDE
INFORMATION.
J
RED X - HORIZONTAL SITUATION INDICATOR (HSI)
1. ADC/AHRS Circuit Breakers - CHECK IN (ESS BUS and
AVN BUS 1). If open, reset (close) circuit breaker. If circuit
breaker opens again, do not reset.
2. Non-Stabilized Magnetic Compass - USE FOR HEADING
INFORMATION.
DISPLAY COOLING ADVISORY
PFD1 COOLING OR MFD1 COOLING ANNUNCIATOR(S)
1. Cabin Heat (CABIN HT) - REDUCE (minimum preferred)
2. Forward Avionics Fan - CHECK (feel for airflow from screen
on glareshield)
IF FORWARD AVIONICS FAN HAS FAILED
3. STBY BAn Switch - OFF (unless needed for emergency
power)
IF PFD1 COOLING OR MFD1 COOLING ANNUNCIATOR
DOES NOT GO OFF WITHIN 3 MINUTES OR IF BOTH PFD1
COOLING AND MFD1 COOLING ANNUNCIATORS COME ON
3. STBY BAn Switch - OFF (land as soon as practical)
U.S.
172SPHAUS-03