Vacuum System And Instruments; Attitude Indicator (Standby Instrument Panel); Low-Vacuum Warning Flag - Textron Cessna Grand Caravan Ex 208B Pilot's Operating Handbook And Faa Approved Airplane Flight Manual

SECTION 7
AIRPLANE AND SYSTEMS DESCRIPTION

VACUUM SYSTEM AND INSTRUMENTS

A vacuum system, refer to Figure 7-14, Vacuum System, provides the
suction necessary to operate the standby attitude indicator. Vacuum is
obtained by passing regulated compressor outlet bleed air through a
vacuum ejector. Bleed air flowing through an orifice in the ejector
creates the suction necessary to operate the indicator. The vacuum
system consists of the bleed air pressure regulator, a vacuum ejector
on the forward left side of the firewall, a vacuum relief valve and
vacuum system air filter on the aft side of the firewall, and the standby
attitude indicator.

ATTITUDE INDICATOR (Standby Instrument Panel)

Standby attitude information is depicted by a vacuum-driven attitude
indicator. 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 superimposed over a symbolic
horizon area divided into two sections by a white horizon bar. The
upper blue sky and the lower ground area have arbitrary pitch
reference lines useful for pitch attitude control. A knob at the bottom of
the instrument is provided for inflight adjustment of the miniature
airplane to the horizon bar for a more accurate flight attitude indication.

LOW-VACUUM WARNING FLAG

The standby attitude indicator includes an orange low-vacuum warning
flag (GYRO) that comes into view when the vacuum is below the level
necessary for reliable gyroscope operation.
The orange low-vacuum warning flag (gyro) is the
only indication of the loss of the vacuum system.
7-116
U.S.
WARNING
CESSNA
MODEL 208B 867 SHP
GARMIN G1000
208BPHCUS-00