CASTLEBERRY Instruments & Avionics
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Document: 0052-1001-0001 Page 2 of 4 Revision B
Model 300-14EL Operator Guide
General Information
This attitude indicator is a precision gyroscopic instrument that provides the pilot with a visual reference of the
aircraft pitch and roll attitude with respect to earth.
To achieve this desired attitude indication, the gyro establishes and maintains a stabilized datum reference
perpendicular to the earth. This rigidity in space is developed by a gimbal mounted high speed self erecting
rotor that generates enough angular momentum to overcome small frictional forces.
This gyro is electrically operated to provide power for the rotor. The spinning mass rotor provides both the
gyroscopic effect and turns impellers to create air flow to provide the leveling torque to keep gyro perpendicular
to the earth.
This gyro is calibrated for standard rate turns. Turns that are faster will create larger errors in pitch and roll
such that when turn is completed it will require more time for gyro to return to a true vertical position.
A Gyro Flag is controlled by a monitor circuit that indicates the integrity of gyro.
Emergency Procedures
In the event that the Gyro Flag comes into view, the accuracy of the gyro is in question until the flag goes back
out of view and the attitude indication is compared with another attitude reference. This situation should also
prompt the verification of the quality of the gyro power source.
Pre-flight Procedures
During pre-flight procedures the attitude gyro must be provided adequate electrical power with vibration to
simulate normal environmental conditions. This is usually achieved by having engines running.
After observing the Gyro Flag go out of view, initial erection is accomplished by pulling the “Pull For Quick
Erect” knob to cage the gyro while the aircraft is in a level or near level position. After caging the gyro will
quickly settle to true level. In a tail-dragger aircraft the caging operation should not be done until after take-off
in level flight. This knob is spring loaded to return caging mechanism to its normal position.
In-flight Procedures
CAUTION: Caging the gyro by pulling the “Pull For Fast Erect” knob while in flight when the aircraft is not
level will cause the gyro to be incorrect. The Parallax indicator may be adjusted anytime to remove parallax
from pilot’s view.
