TM 1-1510-218-10
5-11
NOTE
The following limitations shall be observed. Each column presents limitations. The limits
presented do not necessarily occur simultaneously. Whenever operating limits are exceeded, the
pilot shall record the value and duration of the condition encountered on DA Form 2408-13-1.
Table 5-1. Engine Operating Limitations
OPERATING
CONDITION
TORQUE
PERCENT
(1)
MAXIMUM
OBSERVED
TGT °C
GAS GENERATOR
RPM N1 (2)
%
PROP
RPM
N2
OIL
PRESS PSI
(3)
OIL TEMP °C
(4) (5)
STARTING
–––
1000 (6)
–––
–––
–––
–40
LOW IDLE
–––
660 C D
750 T
52 C D
56 T
–––
60 (min)
–40 to 99
TAKEOFF AND
MAX
CONTINUOUS (7)
100
750 C D
800 T
101.5
2000
105–135 C D
100–135 T
10 to 99 C D
0 to 99 T
NORMAL CLIMB
AND CRUISE (8)
–––
725 C D
770 T
–––
–––
–––
–––
MAX
REVERSE
(9)
–––
750
–––
1900
105–135 C D
100–135 T
0 to 99
TRANSIENT
123 (6)
850
102.6 (10)
2200 (6)
–––
0 to 104 (5)
NOTES
(1) Torque limit applies within range of 1600 – 2000 propeller (N2) RPM. Below 1600 RPM torque is limited
to 49%. Above 2000 RPM, torque is limited to 81%.
(2) Turbine tachometer 100.1% maximum below –48 °C.
(3) Normal takeoff and max continuous oil pressures are 105 to 135 psig C D , 100 to 135 psig T , at gas
generator speeds (N1) greater than 27,000 RPM (72%) with oil temperature between 60 °C and 71 °C.
Above 21,000 feet, the minimum oil pressure is 85 psig.
Oil pressure between 60 and 85 psig should be tolerated only for the completion of the flight; and then
only with a power setting not exceeding 49% torque.
Oil pressure below 60 psig is unsafe and requires that either the engine be shut down or a landing be
made as soon as possible, using minimum power required to sustain flight.
During extreme cold starts, oil pressure may reach 200 psig. Fluctuations of ±10 psig are acceptable.
(4) A minimum of 74 °C to 80 °C (165 °F to 176 °F) is recommended. A minimum oil temperature of 55 °C
(130 °F) is recommended for fuel heater operation at takeoff.
(5) Oil temperature limits are –40 °C to 99 °C (–40 °F to 210 °F) C D –44 °C to 99 °C (–45 °F to 210 °F) T
with limited times of 5 minutes at 104 °C (220 °F).
(6) These values are time limited to 5 seconds.
(7) The maximum power available from the engine for takeoff and for emergency use at the pilot’s discretion.
(8) Continued operation above recommended TGT limits will reduce engine life.
(9) These values are time limited to 1 minute.
(10) These values are time limited to 10 seconds.
