TM 1-1520-238-T-4
6–60.2
Change 5
6–13.
DRIVE SYSTEM – DYNAMIC MAINTENANCE OPERATIONAL CHECK (cont)
6–13
M58-283
TYPICAL DIFFERENTIAL
PRESSURE INDICATOR
SIGHT
GAGE
Figure 6–21.
Engine NGBs Sight Gage and Typical Differential Pressure Indicator
Task
Result
w. On engine NGBs, check oil level in sight
gage (fig. 6–21).
If engine nose gearboxes oil loss is indicated, go to
paragraph 6–80.
x. Visually inspect differential pressure
indicators (fig. 6–21) located on the left
NGB, right NGB, accessory oil pump and
main transmission. Are all indicators in the
retracted position?
If any indicator is extended, reset indicator and go to
step y.
y. Start/operate engines 1 and 2
(TM 1-1520-238-CL). Ground run at 100%
NR for five minutes.
z. Shut down helicopter (TM 1-1520-238-CL).
aa. Visually inspect differential pressure
indicators located on the left NGB, right
NGB, accessory oil pump and main
transmission. Are all indicators in the
retracted position?
If indicator is extended, remove filter element
(TM 1-1520-238-23) and check for contamination.
If contaminated replace filter element
(TM 1-1520-238-23).
If contamination is not present, replace differential
pressure indicator (TM 1-1520-238-23).
4. Perform DRIVE SYSTEM – POWER DOWN (para 6–11).
END OF TASK
