GRUMMAN AMERICAN
FOR TRAINING USE ONLY – SECTION 1
MODEL GA-7/COUGAR
GENERAL
1-9
Issued: April 10, 1978
V
X
Best Angle-of-Climb Speed is the speed which results in the greatest gain of altitude in a given
horizontal distance.
V
Y
Best Rate-of-Climb Speed is the speed which results in the greatest gain in altitude in a given
time.
METEOROLOGICAL TERMINOLOGY
°C
°C is temperature in degrees Celsius (Centigrade).
°F
°F is temperature in degrees Fahrenheit.
ISA
International Standard Atmosphere in which: The air is a dry perfect gas. The temperature at
sea level is 15° Celsius (59° Fahrenheit). The pressure at sea level is 29.92 inches Hg. (1013.2
mb). The temperature gradient from sea level to the altitude at which the temperature is -
56.5°C (-69.7°F), is -0.00198° (-0.003566°F) per foot and zero degrees above that altitude.
OAT
Outside Air Temperature is the free air static temperature. It is expressed in either degrees
Celsius (Centigrade) or degrees Fahrenheit.
Indicated
Pressure
Altitude
Indicated Pressure Altitude is the altitude read from an altimeter when the barometric
subscale has been set to 29.92 inches of mercury (1013 mb).
Pressure
Altitude
Pressure Altitude is altitude measured from standard sea level pressure (29.92 In. Hg.) by a
pressure or barometric altimeter. It is the indicated pressure altitude corrected for position
and instrument error. In this Handbook, altimeter instrument errors are assumed to be zero.
Position errors may be obtained from the altimeter correction chart.
Station
Pressure
Station pressure is actual atmospheric pressure at field elevation.
Wind
The wind velocities recorded as variables on the charts in this handbook are to be
understood as the headwind or tailwind components of the reported winds.
ENGINE POWER TERMINOLOGY
BHP
Brake Horsepower is the power developed by the engine.
Critical Altitude The maximum altitude at which, in standard temperature, it is possible to maintain a
specified power.
Maximum
Continuous
Power
The power developed in a standard atmosphere from sea level to the critical altitude at the
maximum RPM and manifold pressure approved for use during periods of unrestricted
duration.
RPM
The revolutions per minute (RPM) of an engine is the rotational speed of the propeller shaft
as indicated on a tachometer.
Manifold
Pressure
Manifold Pressure is the absolute pressure in the intake manifold of the engine.
