TM 55-1510-220-MTF
PROCEDURE
TROUBLESHOOTING
REFERENCE
F.
AVIONICS FLIGHT CHECKS (CONT)
6)
Push off the STAB OFF button to restore stabiliza- tion.
(7) Pattern observed in step
(5) should not change. If the pattern shifts either left or right around the second range marks,
ground check leveling of the gyro and accuracy of the horizon indicator. Use TILT control to
find exact error.
(8) Roll the aircraft 20° right. For perfect stabilization, the terrain band should be displayed
throughout the third range marks.
(9) If the terrain band shifts to the right around the second range marks, increase tilt angle using
TILT control until pattern is displayed throughout the third range marks. Note new position of
TILT control. It should not be more than two degrees above that noted in step (5).
(10) If the terrain band shifts (in step (8) to the left around the second range marks, decrease tilt
angle using TILT control until pattern is displayed
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