Marine Installation Manual
2021-08
2-13
2 Engine Power and Speed
2.7 Prohibited operation area
X72DF
2.7
Prohibited operation area
Within the higher speed range of the engine there is a prohibited operation area
defined by a minimum engine power requirement. During normal operation, in
-
cluding Controllable Pitch Propeller (CPP) at zero pitch operation, the engine
will not enter this prohibited area. However, if the propeller is disconnected from
the engine, the engine would be capable of entering the prohibited operation
area, which is strictly forbidden.
Figure 2
-
7 The prohibited operation area (CMCR speed = R1
—
R2)
[% R1 - R2] 40
50
60
70
80
90
100
[rpm]
110
100
90
80
70
60
50
40
30
20
10
0
5
7
8
Field A
Prohibited operation area
17 [% Rx]
CMCR [Rx]
Engine power [% Rx]
Engine speed
5.8 [% Rx]
11
12
E
F
44.5
35.6
53.4
62.3
71.2
80.1
89
X72DF
SM-0396
NOTE
It is strictly forbidden for the engine to enter the prohibited operation
area.
