Cessna 1971 Super Skymaster Owner's Manual page 52

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PROPELLER ANTI-ICE SYSTEM
A propeller anti-ice system is available to facilitate all-weather
operation. The system is operated by a rocker type switch located on the
left hand switch and control panel. When the switch is placed in the "ON"
position, current flows to an anti-ice timer which supplies electric power
in cycles every 30 seconds to elements in the anti-icing boots located on
the propeller blades of the front engine (anti-icing required on front engine
only). Operation of the anti-ice system can be checked by a propeller
anti-ice ammeter located on the extreme right side of the instrument
panel. The system is protected by a circuit breaker located in the circuit
breaker panel.
NORMAL OPERATION.
(1) Master Switch -- "ON. "
(2) Propeller Anti-Ice Circuit Breaker -- Check in.
(3) Propeller Anti-Ice Switch -- "ON. "
(4) Propeller Anti-Ice Ammeter -- Check in green arc range (7 to
12 amps).
NOTE
To check the heating elements and the anti-ice timer
for one complete cycle, the system must be left on for
approximately 1-1/2 minutes. Ammeter readings must
remain
in
the green arc except during momentary cycle
change.
IMPORTANT
If
the ammeter indicates unusually high or low amperage
during the 30 second cycle of operation, a malfunction has
occurred and it is imperative that the system be turned
off. Uneven anti-icing may result, causing propeller un­
balance and engine roughness.
(5) When anti-icing is no longer needed, move propeller anti-ice
switch to the off position.
r--RADIOSELECroR-swrrCHis-
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RADIO SELECTOR SWITCH OPERATION.
Operation of the radio equipment is normal as covered in the respec ­
tive radio manuals. When one or more radios is installed, an audio
switching system is necessary. The operation of this switching system
is described below.
TRANSMITTER SELECTOR SWITCH
" The transmitter selector switch, labeled "COMM,
It
has two positions.
.f'
When two transmitters are installed, it is necessary to switch the micro­
i
phone to the radio unit the pilot desires to use for transmission. This is
I.
accomplished by placing the transmitter selector switch in the position
, corresponding to the radio unit which is to be used. The up position selects
, the upper transmitter and the down poSition selects the lower transmitter.
The installation of Cessna radio equipment provides certain audio
back-up capabilities and transmitter selector switch functions that the
pilot should be familiar with. When the transmitter selector switch is
placed in position "1" or "2", the audio amplifier of the corresponding
transceiver is utilized to provide the speaker audio for all radios.
If
the
audio amplifier in the selected transceiver fails, as evidenced by loss of
speaker audio for all radiOS, place the transmitter selector switch in the
other transceiver position. Since an audio amplifier is not utilized for
headphones, a malfunctioning amplifier will not affect headphone operation.
SPEAKER-PHONE SWITCHES.
The speaker" phone switches determine whether .the output of the re ­
ceiver in use is fed to the headphones or through the audio amplifier to the
speaker. Place the switch for the desired receiving system either in the
up position for speaker operation or in the down pOSition for headphones.
AUTOPILOT-OMNI SWITCH.
When a Nav-O-Matic autopilot is installed with two compatible omni
receivers, an autopilot-omni switch, labeled "OMNI 1-2" on some air ­
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