Diamond DA 42 NG, Maintenance Manual

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AIRCRAFT
Navigation
DA 42 NG AMM
Page 2
15 Mar 2018
34-20-00
Doc # 7.02.15
Rev. 4
The attitude gyro incorporates pitch and roll displays that are mechanically linked to a spinning
mass gyroscope. The horizon bar moves behind the symbolic airplane. Precession error is
corrected by the internal erection system or by pulling the PULL TO CAGE knob.
The artificial horizon employs an efficient electrically driven internal vertical gyroscope assembly
incorporating a special air erection mechanism. This mechanism simultaneously erects the pitch
and roll axes of the gyroscope. Movement of the airplane generates a reaction of the display that
simulates the visual reference seen by the pilot when looking outside at the earth's true horizon
line.
C. Standby Attitude Module, if OÄM 42-270 is installed
The left display of the standby attitude module MD302 represents the attitude indicator.
The background of the display consists of the representative white horizon line separating the ‘sky’
(blue) and ‘ground’ (brown).
The roll scale depicted as an arc of graduations representing bank angles of 0 (triangle), 10, 20,
30, 45 (small triangle) and 60. The roll scale can be configured during installation to be fixed to the
sky/horizon or fixed to the top of the display.
The roll pointer is the triangle just below the roll scale and represents the airplane in relation to its
bank angle. It is configured, by definition, to operate conversely to the roll scale behavior. That is,
a rotating scale produces a fixed roll pointer and a fixed roll scale produces a rotating roll pointer.
The pitch scale is depicted as a series of graduations representing pitch angles of every 5°, with
every 10° graduation extended and numbered.
The symbolic airplane will always remain in the center of the display, with the background elements
moving behind it to represent the aircraft’s relative position.
Refer to the manufacturer’s documentation for more information of the standby attitude module.