CESSNA
MODEL 172N
SECTION 7
AIRPLANE & SYSTEMS DESCRIPTIONS
upper corner of the windshield supplies air for the pilot and copilot, and
two ventilators are available for the rear cabin area to supply air to the rear
seat passengers. The airplane may also be equipped with an air condition
ing system. For operating instructions and details concerning this system,
refer to Section 9, Supplements.
PITOT-STATIC SYSTEM AND INSTRUMENTS
The pitot-static system s:.ipplies ram air pressure to the airspeed
indicator and static pressure to the airspeed indicator. vertical speed
indicator and altimeter. The system is composed of either an unheated or
heated pi tot tube mounted on the lower surface of the left wing, an external
static port on the lower left side of the forward fuselage, and the associated
plumbing necessary to connect the instruments to the sources.
The heated pitot system (if installed) consists of a heating element in
the pitot tube, a rocker switch labeled PITOT HT, a 5-amp circuit breaker,
and associated wiring. The switch and circuit breaker are located on the
left side of the switch and control panel. When the pitot heat switch is
turned on, the element in the pitot tube is heated electrically to maintain
proper operation in possible icing conditions. Pitot heat should be used
only as required.
A static pressure alternate source valve may be installed on the switch
and control panel below the throttle, and can be used if the external static
source is malfunctioning. This valve supplies static pressure from inside
the cabin instead of the external static port.
If erroneous instrument readings are suspected due to water or ice in
the pressure line going to the standard external static pressure source, the
alternate static source valve should be pulled on.
Pressures within the cabin will vary with open heater/vents and
windows. Ref er to Section 5 for the effect of varying cabin pressures on
airspeed readings.
AIRSPEED INDICATOR
The airspeed indicator is calibrated in knots and miles per hour.
Limitation and range markings (in KIAS) include the white arc (33 to 85
knots). green arc (44 to 127 knots). yellow arc (127 to 158 knots). and a red
line (158 knots).
If a true airspeed indicator is installed, it is equipped with a rotatable
ring which works in conjunction with the airspeed indicator dial in a
manner similar to the operation of a flight computer. To operate the
1 July 1979
7-31
Содержание 17273274
Страница 8: ......
Страница 18: ......
Страница 38: ......
Страница 72: ......
Страница 92: ......
Страница 94: ......
Страница 116: ......
Страница 118: ......
Страница 123: ...SECTION 7 AIRPLANE SYSTEMS DESCRIPTIONS 7 6 Figure 7 2 Instrument Panel Sheet 1 of 2 CESSNA MODEL 172N 1 July 1979 ...
Страница 158: ......
Страница 160: ......
Страница 176: ......
Страница 178: ......