TM 1-1520-240-MTF
2-3
PRIOR TO MAINTENANCE TEST FLIGHT (CONT.)
Before Interior Check (Cont.)
e. APU START switch — RUN for 3 to 5
seconds. Then START for 2 seconds. Then
release to RUN. Operation of the APU is
controlled by the electronic sensing unit.
NOTE
If the APU ON caution light does not come on, or
if the start is automatically shutdown, set the APU
switch to OFF and check the bite indicators on the
electronic sensing unit for the cause of the
shutdown.
f. APU ON 712 caution light 714A advisory
light — Check on.
g. UTIL HYD SYS caution light — Check out
(30 seconds maximum).
h. APU GEN switch — ON. Check NO. 1 and
NO. 2 RECT OFF caution lights out.
i. POWER XFR NO. 1 and POWER XFR NO.
2 switches — ON. Check NO. 1 and NO. 2
HYD FLT CONTR caution lights out.
WARNING
If either FLT CONTR caution lights do not go
out in 30 seconds after POWER XFR switches
are set to ON, set the POWER XFR switches to
OFF. Do not fly the helicopter.
