Mixing Air Push-Pull Control - Textron Cessna Grand Caravan Ex 208B Pilot's Operating Handbook And Faa Approved Airplane Flight Manual

SECTION 7
AIRPLANE AND SYSTEMS DESCRIPTION
CABIN HEATING, VENTILATING AND DEFROSTING
SYSTEM
(Continued)

MIXING AIR PUSH-PULL CONTROL

A push-pull control, labeled MIXING AIR, GRD-PULL, FLT-PUSH, is
located on the CABIN HEAT switch and control panel. With the push-
pull control in the GRD position (pulled out), warm compressor bleed
valve air is mixed with hot compressor outlet air in the mixer/muffler.
This mode is used during ground operation when warm compressor
bleed valve air is available (at power setting below 92% N
used as additional bleed air heat to augment the hot compressor outlet
bleed air supply during periods of cold ambient temperature. With the
push-pull control in the FLT position (pushed in), cabin return air is
mixed with the hot compressor outlet air in the mixer/muffler. This
recirculation of cabin return air enables the heating system to maintain
the desired temperature for proper cabin heating. If desired, the FLT
position of the push-pull control can be used on the ground when
ambient temperatures are mild and maximum heating is not required.
In this mode, the excess warm compressor bleed valve air available at
power settings below 92% N
air valve.
The MIXING AIR push-pull control should always be in
the FLT position (pushed in) when the airplane is in
flight. Cabin return air must be allowed to flow through
the mixing valve and blend with hot compressor outlet
air during high engine power operation in order to
maintain proper temperature in the cabin heat
distribution system. If the FLT position is not used
during flight, the system may overheat and cause an
automatic shutdown.
7-110
U.S.
is exhausted overboard from the mixing
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CAUTION
CESSNA
MODEL 208B 867 SHP
GARMIN G1000
) and can be
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208BPHCUS-00