The-pitch and roll output levels from the vertical gyro are
governed by the 115 volt, 400 Hz excitation and the linearity of
the gyro, plus the ability of the gyro to follow the motion of the
aircraft. The accuracy contributed by the antenna is its ability
to respond to the gyro outputs. As a result of these factors, the
stabilization system accuracy can vary up to + 10% of the
pitch or roll angle of the aircraft.
(1) Fly to an altitude above 10,000 feet.
(2) MODE switches - WX.
(3) RANGE switches - 120 or 60.
(4) STAB OFF switch - Push ON.
(5) While flying level (0° pitch, 0° roll), adjust TILT control to obtain a video pattern throughout
the upper range marks. Note TILT control setting. if the inner ring of video is not parallel to the
range mark, the error is caused by mechanical displacement of the antenna about the roll axis
of the aircraft. Use TILT control to determine exact error. Correct on ground, if necessary,
before further inflight calibration.