TM 55-1520-240-23-3
4-3
TURBINE ENGINE ANALYSIS CHECK (TEAC)
(Continued)
4-3
12.
Raise thrust lever slowly.
13.
Set ENGINE CONDITION LEVER (ECL) engine
not being TEACed to GROUND. Maintain 100
percent rotor rpm using ENGINE BEEP TRIM
switch.
14.
Continue increasing thrust and increasing NO. 1
& NO. 2 BEEP TRIM switch until gas producer
(N1) speed for engine being TEACed stabilizes
at maximum and rotor rpm falls to 98 percent.
Maintain N1 and 98 percent rotor rpm using
thrust control and NO. 1 & NO. 2 ENGINE BEEP
TRIM switch.
Do not adjust thrust until rotor rpm
begins to decrease. An engine
overspeed can occur if thrust is
adjusted before rotor rpm begins to
decrease.
Do not exceed following limits:
a. Power turbine inlet temperature
(PTIT) 890ºC.
b. N1 — 105 percent.
c. Airspeed — 140 KIAS.
d. Engine torque — 123 percent.
15.
Stabilize rotor rpm at 98 percent for 2 to 3
minutes, then record the following:
a.
N1 speed
b.
Rotor rpm
c.
FAT
d.
PTIT
e.
Torque
f.
Pressure altitude
16.
Determine corrected N1 speed.
a.
Enter c from step 15 on chart (6) at FAT (7).
b.
Enter a from step 15 on chart (6) at N1 speed
(9). Note intersection of lines.
17.
Determine Torque Available.
a.
Enter c from step 15 on chart (10) at FAT.
Draw line vertically to f from step 15 (recorded
pressure altitude).
b.
Draw line horizontally from point determined
in step 17a left to the torque available scale.
Determine torque available.
4-28
