Standby Airspeed Indicator; Standby Altimeter; Standby Compass (Magnetic Compass) - Beechcraft Baron G58 Pilot Operating Handbook

Section 7
Systems Description Model G58

STANDBY AIRSPEED INDICATOR

A standby mechanical airspeed indicator is mounted on the
right side of the instrument panel. The indicator is connected to
the airplane's pitot and static systems along with the Air Data
Computer. The airspeed indicator remains operational in the
event of complete electrical failure and will also operate with
the alternate static source. Lighting is provided by the Right
Bus and is controlled by the STANDBY INST rheostat located
on the right subpanel.

STANDBY ALTIMETER

A standby mechanical altimeter is located on the right side of
the instrument panel. It is connected to the airplane's normal
and alternate static systems along with the ADC and is inde-
pendent of the airplane's electrical system except for lighting.
Lighting is provided by the Right Bus and is controlled by the
STANDBY INST rheostat located on the right subpanel.

STANDBY COMPASS (MAGNETIC COMPASS)

The standby compass is a self contained non-stabilized com-
pass that will provide magnetic heading should the electric
heading reference fail from the Attitude and Heading Refer-
ence System (AHRS) or become unavailable from a loss of
electric power. A compass correction card mounted below the
compass provides "steer to" heading for each thirty degrees of
heading. The magnetic compass is compensated and correc-
tion values are determined with all avionics equipment operat-
ing and the engines running. The Magnetic compass is erratic
when the heated windshield is in operation. The compass has
a light powered by the Right Bus through the CLOCK circuit
breaker. The light is turned on and off by a switch on the right
side of the pilot's control wheel labeled MAP OAT COMP.
7-86 May, 2015