TM 1-1520-238-MTF
4-31
Change 2
O. TORQUE REPEATABILITY CHECK.
NOTE
This check may be done on the ground or
at altitude. If it is done on the ground, the
helicopter should be headed into the wind
to reduce the effects of exhaust gas in-
gestion. If it is done at altitude, all steps
will be done at the same altitude. In either
case, all steps will be done at the same
FAT and Np.
The procedures in TM 1-1520-238-10
should be referred to when starting en-
gines.
1. Start the engine and slowly increase engine
power until TGT reaches 650 C. If temperature
exceeds 650 C, reduce power until TGT is
below 600 C. Then slowly approach 650 C
again by slowly increasing engine power.
2. Stabilize TGT at 650 C for one minute. Record
torque, NG, and TGT.
3. Increase power until TGT is 700 – 750 C.
4. Slowly reduce power until TGT is 650 C. If
temperature is below 650 C, increase power
until TGT is 700 – 750 C. Then slowly reduce
power until TGT is 650 C.
5. Stabilize TGT at 650 C for one minute. Record
torque, NG and TGT.
6. With helicopter on the ground, reduce power
quickly to ground idle speed. Record torque, NG
and TGT with engine stabilized at ground idle
speed.
