TM 55-1510-219-10
Vx
Best angle of climb speed.
Vxse
Best single-engine angle of climb speed.
Vy
Best rate of climb speed.
Vyse
The best single engine rate of climb speed.
METEOROLOGICAL TERMINOLOGY.
Altimeter Setting
Barometric pressure corrected to sea level.
°C
Degrees Celsius.
°F
Degrees Fahrenheit.
FAT
Free air temperature is the free air static temperature, obtained either from ground
meteorological sources or from inflight temperature indications adjusted for com-
pressibility effects.
Indicated Pressure
The number actually read from an altimeter when the barometric scale (Kollsman
Altitude
window) has been set to 29.92 inches of mercury (1013 millibars).
ISA
International standard atmosphere in which:
a. The air is a dry perfect gas;
b. The temperature at sea level is 59 degrees Fahrenheit, 15 degrees Celsius;
c. The pressure at sea level is 29.92 inches Hg;
d. The temperature gradient from sea level to the altitude at which the temperature
is -69.7 degrees Fahrenheit is -0.003566 Fahrenheit per foot and zero above that al-
titude.
Pressure Altitude
Indicated pressure altitude corrected for altimeter error
(press alt)
SL
Sea level.
Wind
The wind velocities recorded as variables on the charts of this manual are to be un-
derstood as the headwind or tailwind components of the actual winds at 50 feet
above runway surface (tower winds).
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 temper-
ature (ITT) limited.
High Idle
Obtained by placing the condition lever in the HIGH IDLE position.
HP
Horsepower.
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 opera-
tion.
Normal Rated Climb
The maximum power available from an engine for continuous normal climb opera-
Power
tions.
Normal Rated Power
The maximum power available from an engine for continuous operation in cruise
(with lower ITT limit than normal rated climb power).
B-2
