TM 1-1520-238-T-5
8–168
8–91.
FLIGHT INSTRUMENTS – MAINTENANCE OPERATIONAL CHECK (cont)
8–91
Task
Result
h. On pilot EXT LT/INTR LT panel (fig. 8–47),
turn INST control to BRT.
If accelerometer indicator, VSI, barometric altimeter,
magnetic compass, airspeed indicator and SAI
(fig. 8–48) edge–lights do not light, refer to
TM 1-1520-238-T-6 to troubleshoot pilot edge–lights.
If pilot airspeed indicator edge–lighting does not light,
go to paragraph 8–96.
If pilot accelerometer indicator edge–lighting does not
light, go to paragraph 8–97.
If pilot barometric altimeter edge–lighting does not
light, go to paragraph 8–98.
If pilot VSI edge–lighting does not light, go to
paragraph 8–99.
If pilot SAI edge–lighting does not light, go to
paragraph 8–100.
If pilot magnetic compass lamp does not light, replace
lamp (TM 1-1520-238-23). If lamp still does not light,
go to paragraph 8–101.
i. Turn and release PULL TO CAGE knob to
pilot SAI (fig. 8–48) then turn knob clockwise
and counterclockwise.
If fixed aircraft symbol does not move up and down
on face of gyrosphere, replace SAI
(TM 1-1520-238-23).
j. Check STBY ATTD circuit breaker on pilot
center circuit breaker panel (fig. 8–46) is
closed.
k. Check OFF flag on SAI (fig. 8–48).
If OFF flag is visible, go to paragraph 8–102.
l. Pull and turn PULL TO CAGE knob on pilot
SAI. Check OFF flag on SAI.
If OFF flag is not visible, replace pilot SAI
(TM 1-1520-238-23).
m. On pilot VSI (fig. 8–48), set indicator to
0 FPM using adjust screw on face of
indicator.
If VSI does not adjust 0 FPM, replace pilot VSI
(TM 1-1520-238-23).
n. On CPG VSI (fig. 8–45), set indicator to
0 FPM using adjust screw on face of
indicator.
If VSI does not adjust to 0 FPM, replace CPG VSI
(TM 1-1520-238-23).
