TM 55-1510-215-10
B-3. 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. These powers are torque or
temperature (ITT) limited.
High Idle
Obtained by placing the Condition Lever in the HIGH IDLE position.
HP
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
The maximum power available from an engine for continuous normal
Climb Power
climb operations.
Normal Rated
The maximum power available from an engine for continuous operation i n
Power
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
The maximum power available from an engine for takeoff, limited to
Power
periods of five minutes duration.
B-4. Control and Instrument Terminology.
Condition Lever (Fuel
The fuel shut-off lever actuates a valve in the fuel control unit which controls the
Shut-off Lever)
flow of fuel at the fuel control out let and regulates the idle range from LO to
HIGH.
Interstage
Thermocouple probes wired in parallel indicate the temperature between the
Turbine Temperature
compressor and power turbines.
(ITT)
N1 Tachometer (Gas
The tachometer registers the RPM of the gas generator with 100%
Generator RPM)
representing a gas generator speed of 37,500 RPM.
Power Lever (Gas
This lever serves to modulate engine power from full reverse thrust to
Generator N1 RPM)
takeoff. The position for idle represents the lowest recommended level of power
for flight operation.
Propeller Control
This lever requests the control to maintain RPM at a selected value and, in
Lever (N2 RPM)
the maximum decrease RPM position, feathers the propeller.
Propeller Governor
This Governor will maint ain the selected propeller speed requested by the
propeller control lever.
Change 7 B-3
