Stall Warning System; Attitude Indicator; Directional Indicator; Suction Gage - Cessna TR182 1979 Pilot Operating Handbook

SECTION 7
AIRPLANE
&
SYSTEMS DESCRIPTIONS
CESSNA
MODELTR182
ATTITUDE INDICATOR
The attitude indicator gives a visual indication of flight attitude. Bank
attitude is presented by a pointer at the top of the indicator relative to the
bank scale which has index marks at 10°,20°,30°,60°, and 90°either side of
the center mark. Pitch and roll attitudes are presented by a miniature
airplane in relation to the horizon bar. A knob at the bottom of the
instrument is provided for in-flight adjustment of the miniature airplane
to the horizon bar for a more accurate flight attitude indication.
DIRECTIONAL INDICATOR
The directional indicator displays airplane heading on a compass card
in relation to a fixed simulated airplane image and index. The directional
indicator will precess slightly over a period of time. Therefore, the
compass card should be set in accordance with the magnetic compass just
prior to takeoff, and occasionally re-adjusted on extended flights. A knob
on the lower left edge of the instrument is used to adjust the compass card
to correct for any precession.
SUCTION GAGE
The suction gage, located below the flight instruments, is calibrated in
inches of mercury and indicates suction available for operation of the
attitude and directional indicators. The desired suction range is 4.6 to 5.4
inches of mercury. A suction reading below this range may indicate a
system malfunction or improper adjustment, and in this case, the indica-
tors should not be considered reliable.
STALL WARNING SYSTEM
The airplane is equipped with a vane-type stall warning unit, in the
leading edge of the left wing, which is electrically connected to a stall
warning horn under the map compartment. A 5-amp push-to-reset circuit
breaker labeled STALL WARN, on the left side of the switch and control
panel, protects the stall warning system. The vane in the wing senses the
change in airflow over the wing, and operates the warning horn at
airspeeds between 5 and 10 knots above the stall in all configurations.
If the airplane has a heated stall warning system, the vane and sensor
unit in the wing leading edge is equipped with a heating element. The
heated part of the system is operated by the PITOT HEAT switch, and is
protected by the PITOT HEAT circuit breaker.
The stall warning system should be checked during the pre-flight
7-44
1 October 1978
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