TM 1-1520-238-MTF
4-11
NOTE
If helicopter is equipped with two FAT gages
and the readings are different, the higher
reading must be used.
6. Record date, A/C hours, FAT, pressure altitude,
and TGT on HIT log sheet in helicopter logbook.
NOTE
Steps 7 thru 9 contain instructions for per-
forming the anti-ice Check.
7. If NG is less than 90% and FAT is 15 C or
below, then increase collective to 90%. If NG is
less than 90% and FAT is above 15 C, then
increase collective to 94%.
8. For engine being checked, set ANTI-ICE switch
to ON and note the following:
a. Increase in TGT of at least 30 C.
b. ANTI-ICE advisory light comes on.
c.
ANTI-ICE panel ENG INLET advisory
light remains on after 90 seconds.
NOTE
Do not cycle anti-ice bleed and start valve
more than once to determine proper op-
eration.
Anti-ice valve malfunction can cause en-
gine flameout at low power settings or
during rapid collective movements.
If any part of the anti-ice check fails, do
not fly helicopter.
