TM 55-1510-222-10
POWER TERMINOLOGY.
Beta Range
The region of the power lever control which is aft of the idle stop and forward of
reversing range where blade pitch angle can be changed without a change of gas generator
RPM.
Cruise Climb
Is the maximum power approved for normal climb. This power is torque or temperature (ITT)
limited.
High Idle
Obtained by placing the condition lever in the HIGH IDLE position.
SHP
Shaft horsepower. That horsepower imparted to the propeller shaft.
Low Idle
Obtained by placing the condition lever in the LO IDLE position.
Maximum Cruise
Is the highest power rating for cruise and is not time limited.
Power
Maximum Power
The maximum power available from an engine for use during an emergency operation.
Normal Rated Climb
The maximum power available from an engine for continuous normal climb operations.-
Power
Normal Rated Power
The maximum power available from an engine for continuous operation in cruise (with lower ITT
limit than normal rated climb power).
Reverse Thrust
Obtained by lifting the power levers and moving them aft of the beta range.
RPM
Revolutions Per Minute.
Takeoff Power
The maximum power available from an engine for takeoff, limited to periods of five minutes
duration.
CONTROL AND INSTRUMENT TERMINOLOGY.
Condition Lever (Fuel
The fuel shut-off lever actuates a valve in the fuel control unit which controls the flow
Shut-off Lever)
of fuel at the fuel control outlet and regulates the idle range from LO to HIGH]
N1 Tachometer (Gas
The tachometer registers the RPM of the gas generator with 100% representing a gas
Generator RPM)
generator speed of 37,500 RPM.
Power Lever (Gas Gen-This lever serves to modulate engine power from full reverse thrust to take-off. The
erator N1 DRPM)
position for idle represents the lowest recommended level of power for flight opera-
tion.
Propeller Control
This lever requests the control to maintain RPM at a selected value and, in the maximum
Lever (N2RPM)
decrease RPM position, feathers the propeller.
Propeller Governor
This Governor will maintain the selected propeller speed requested by the propeller control lever.
Torquemeter
The torquemeter system determines the shaft output torque. Torque values are obtained by
tapping into two outlets on the reduction gear case and recording the differential pressure from
the outlets.
B-3
