AVIONICS FLIGHT CHECKS (CONT)
SECT scan angle pushbutton selector
switch - 120 or 60.
STAB pushbutton selector switch - Push
OFF to remove stabilization.
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 in-flight calibration.
Attitude stabilization pushbutton selector
switch - Push on to restore stabilization.
Verify that pattern does not change. If
the pattern shifts either left or right,
ground check leveling of the gyro and
accuracy of the horizon indicator. Use
TILT control to find exact error.
Roll the aircraft 20 right. For perfect
stabilization, the terrain band will be
displayed throughout the third range
If the terrain band shifts to the right
around the second range