TM 1-1520-238-MTF
4-15
c.
ANTI-ICE panel ENG INLET advisory
light goes off with a delay of approximately
90 seconds.
12. Repeat steps 3 thru 11 twice. This completes
logging of data. Remaining steps can be done
after engine is shut down.
13. Using HIT baseline worksheet (fig 5-2, Chapter
5), calculate average indicated TGT for above
three readings.
NOTE
When using TGT reference table, FAT must
be rounded up, the pressure altitude must
be rounded off to the nearest value, if appli-
cable.
EXAMPLE
a. If FAT is 14 C, use 15 C. Or, if FAT is 46
C, use 50 C.
b. If pressure altitude is between -249 feet and
249 feet, use 0 feet. Or, if pressure alitude is
between 250 feet and 749 feet, use 500
feet.
14. Find indicated TGT in
(fig 5-3, Chapter 5) or
(fig 5-4, Chapter 5) to determine actual
TGT for recorded FAT and pressure altitude.
15. Subtract table TGT on HIT baseline worksheet
(fig 5-2, Chapter 5) from average indicated TGT
(fig 5-3, Chapter 5) or
(fig 5-4,
Chapter 5).
16. Establish TGT upper and lower limits by adding
20 C (68 F) to answer in step 15 and by
subtracting 20 C (68 F) from answer in step
15. Record TGT upper and lower limits on HIT
logsheet in helicopter logbook.
