SECTION 1
CESSNA
GENERAL
MODEL 172S NAV III
METEOROLOGICAL TERMINOLOGY
OAT
Outside Air Temperature is the free air static
temperature. It may be expressed in either degrees
Celsius or degrees Fahrenheit.
Standard
Standard Temperature is 15°C at sea level
Temperature
pressure altitude and decreases by 2°C for each
1000 feet of altitude.
Pressure
Pressure Altitude is the altitude read from an
Altitude
altimeter when the altimeter's barometric scale has
been set to 29.92 inches of mercury (1013 mb).
ENGINE POWER TERMINOLOGY
BHP
Brake Horsepower is the power developed by the
engine.
RPM
Revolutions Per Minute is engine speed.
Static
Static RPM is engine speed attained during a full
RPM
throttle engine runup when the airplane is on the
ground and stationary.
MAP
Manifold Absolute Pressure is the absolute
pressure measured in the engine induction system.
MAP is measured in units of inches of mercury
(inHG).
Lean
Decreased proportion of fuel in the fuel-air mixture
Mixture
supplied to the engine. As air density decreases, the
amount of fuel required by the engine decreases for
a given throttle setting. Adjusting the fuel-air mixture
to provide a smaller portion of fuel is known as
"leaning" the mixture.
Rich
Increased proportion of fuel in the fuel-air mixture
Mixture
supplied to the engine. As air density increases, the
amount of fuel required by the engine increases for a
given throttle setting. Adjusting the fuel-air mixture to
provide a greater portion of fuel is known as
"richening" the mixture.
(Continued Next Page)
1-10 U.S.
172SPHAUS-00