MD Helicopters MILVIZ MD530F, Rotorcraft Flight Manual, Page: 52 / 326

MD 500
(Models 369HE/HS/HM) ROTORCRAFT FLIGHT MANUAL CSP
−
HE/HS
−
1
FAA Approved
Revision 6
2
−
10
2
−
9. POWERPLANT LIMITATIONS ALLISON 250
−
C20
Engine torque limits:
Maximum takeoff power (5 minute): 64.5 psi torque
Maximum continuous: 56.0 psi torque
Transient torque limits:
72.0 psi torque for 10 seconds at 104 percent N
2.
80.0 psi torque for 3 seconds at 104 percent N
2.
Turbine Outlet Temperature limits:
Maximum takeoff (5 minute): 793
°
C
Maximum continuous: 737
°
C
Maximum for starting (lightoff): 150 ° C
Transient limits:
During start and shutdown: 793
°
C to 927
°
C for up to 10 seconds with a
momentary peak temperature of 927
°
C for not more than 1 second.
During power changes in flight: 793
°
C to 843
°
C for 6 seconds.
Gas Producer (N
1
) speed limits:
Maximum continuous: 104%
Ground idle speed: 61 − 65%
Transient limits:
104 − 106% for 15 seconds
Power Turbine (N
2
) speed limits:
Normal Power On operation: 103% to 104% N
2
.
Transient overspeed limit (15 seconds maximum): 113% at idle power vary-
ing linearly to 108% at 64.5 psi torque.
Avoid steady state operations between 75% and 88%. Transition through the
speed avoid range is to be accomplished as quickly as possible.
CAUTION
Maximum allowable time in the speed avoid range is 1 minute.
NOTE
: Refer to Rolls
−
Royce CEB A
−
1400.
Engine oil system limits:
Flight operation temperature limits: 0
°
C to 107
°
C
NOTE
: These engine oil temperature limits pertain to all gauge configurations. 0°C is
when the needle is at the bottom of the yellow/green arc.
Flight operation pressure limits:
94.2 percent N
1
and above: 115 − 130 psig
78.5 to 94.2 percent N
1
: 90 − 130 psig
78.5 percent N
1
and below: 50 − 130 psig