TM 55-1510-220-10
Table 5-1. Engine Operating Limitations
GAS
OPERATING
TORQUE
MAXIMUM
GENERATOR
PROP
OIL
OIL
CONDITION
SHP
PERCENT
OBSERVED
RPM N1 (10)
RPM
PRESS
TEMP
(1)
TGT °C
RPM %
N2 (11)
PSI (2)
°C
TAKEOFF (3)
850
100%
750
38,100
101.5
2000
105 to 135
10 to 99
MAX CONT
850
100% (4)
750
38,100
101.5
2000
105 to 135
10 to 99
MAX CLIMB
850
100% (4)
725
38,100
101.5
2000
105 to 135
0 to 99
MAX CRUISE
HIGH IDLE
-
-
-
-
(5)
-
-
-40 to 99
LOW IDLE
-
-
660 (6)
19,500
52(min)
-
60(min)
-40 to 99
STARTING
-
-
1000 (7)
-
-
-
-
-40(min)
TRANSIENT
-
123% (7)
850
38,500
(8)
102.6
(8)
2200 (7)
-
0 to 104 (3)
MAX
REVERSE
(9)
-
-
750
-
88
1900
105 to 135
0 to 99
NOTES:
(1) Torque limit applies within range of 1600-2000
propeller RPM (N2). Below 1600 RPM, torque is limited
to 49%.
(2) Normal takeoff and maximum continuous operation
oil pressure at gas generator speeds above 72% with oil
temperature between 60 and 71 °C is 105 to 135 PSIG up
to 21,000 feet.
Above 21,000 feet, the minimum oil pressure is 85 PSIG.
Plus or minus 10 PSIG fluctuations are acceptable. Oil
pressure between 60 and 85 PSIG should be tolerated
only for the completion of the flight at power setting not to
exceed 49% torque. Oil pressures below 60 PSIG are
unsafe and require that either the engine be shut down or
a landing be made as soon as possible, using the
minimum power required to sustain flight. During
extremely cold starts, oil pressure may reach 200 PSI.
(3) These values are time limited to 5 minutes.
(4) Cruise torque values vary with altitude and
temperature.
(5) At approximately 70% N1.
(6) High TGT at ground idle may be corrected by
reducing accessory load and/or increasing N1 RPM.
(7) These values are time limited to 5 seconds.
(8) These values are time limited to 10 seconds.
(9) This operation is time limited to 1 minute.
(10) For every 56C below - 48C ambient temperature,
reduce maximum allowable N1 by 1.6%.
(11) Torque is limited to 81% for sustained operation
above 2000 propeller RPM.
5-7
