Cirrus SR20 Maintenance Manual

C I R R U S
A I R P L A N E M A I N T E N A N C E M A N U A L
1. GENERAL
This section contains information pertaining to those portions of the system which use magnetic, gyro-
scopic, and inertia forces. Included is the magnetic compass, attitude indicator, and magnetometer.
Figure 34-001)
A. Magnetic Compass
The magnetic compass, mounted to the fuselage above the windshield, contains a circular compass
card, visible through the compass case window, suspended in alcohol solution. The compass is
equipped with compensating magnets and has two adjusting set screws, one for North-South adjust-
ment and one for East-West adjustment. These set screws are located behind the access plate on the
compass face. Light is integral and controlled by the instrument light rheostat on the bolster switch
panel.
B. Attitude Indicator
Serials w/o MD302 Standby Attitude Module: The attitude indicator is an electrically driven gyro that
displays a pictorial horizon and provides the pilot with a visual indication of the airplane's pitch and roll
attitude by sensing pitching and rolling movements about the airplane's lateral and longitudinal axis.
The attitude indicator is mounted on the LH bolster panel. 28 VDC for attitude gyro operation is sup-
plied through the 5-amp STDBY ATTD A circuit breaker on Essential Bus 1 and the 5-amp STDBY
ATTD B circuit breaker on Main Bus 1.
Serials w/ MD302 Standby Attitude Module: The optional MD302 Standby Attitude Module is a com-
bined standby airspeed indicator, standby altimeter, and standby attitude indicator located in the LH
bolster panel. The unit uses electronic sensors to provide attitude information. The attitude indicator
displays a pictorial horizon and provides the pilot with a visual indication of the airplane's pitch and roll
attitude by sensing pitching and rolling movements about the airplane's lateral and longitudinal axis. 28
VDC for MD302 Standby Attitude Module operation is supplied through the 5-amp STDBY ATTD A cir-
cuit breaker on Essential Bus 1 and the 5-amp STDBY ATTD B circuit breaker on Main Bus 1.
For additional maintenance practices on the MD302 Standby Attitude Module, see Flight Environmen-
tal Systems. (Refer to 34-10)
C. Magnetometer
A GMU 44 magnetometer, mounted outboard in the wing, provides three axis magnetic field vector
measurements and interfaces with the GSU 75 ADAHRS. A second magnetometer, located adjacent
to the first, may be installed by option. 28 VDC for the standard magnetometer is supplied through the
5-amp PFD A circuit breaker on Essential Bus 1. 28 VDC for the optional magnetometer is supplied
through the 5-amp PFD B circuit breaker on Main Bus 2.
The GMU 44 magnetometer is integral to the Perspective
view of the Perspective
42-00)
EFFECTIVITY:
All
ATTITUDE AND DIRECTION
+
Avionics system, refer to Chapter 42, Integrated Modular Avionics.
+
Integrated Avionics system. For an over-
M O D E L S R 2 0
(See
(Refer to
34-20
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1 Feb 2017