SECTION 1
CESSNA
GENERAL
MODEL 172RG
NMPG
Nautical Miles Per Gallon is the distance (in nautical
miles) which can be expected per gallon of fuel consumed
at a specific engine power setting and/ or flight configura-
tion.
g
g is acceleration due to gravity.
WEIGHT AND BALANCE TERMINOLOGY
Reference
Reference Datum is an imaginary vertical plane from
Datum
which all horizontal distances are measured for balance
purposes.
Station
Station is a location along the airplane fuselage given in
terms of the distance from the reference datum.
Arm
Arm is the horizontal distance from the reference datum to
the center of gravity (C.G.) of an item.
Moment
Moment is the product of the weight of an item multiplied
by its arm. (Moment divided by the constant 1000 is used in
this handbook to simplify balance calculations by reduc-
ing the number of digits.)
Center of
Center of Gravity is the point at which an airplane, or
Gravity
equipment, would balance if suspended. Its distance from
(C.G.)
the reference datum is found by dividing the total moment
by the total weight of the airplane.
C.G.
Center of Gravity Arm is the arm obtained by adding the
Arm
airplane's individual moments and dividing the sum by
the total weight.
C.G.
Center of Gravity Limits are the extreme center of gravity
Limits
locations within which the airplane must be operated at a
given weight.
Standard
Standard Empty Weight is the weight of a standard air-
Empty
plane, including unusable fuel, full operating fluids and
Weight
full engine oil.
Basic Empty
Basic Empty Weight is the standard empty weight plus the
Weight
weight of optional equipment.
Useful
Useful Load is the difference between ramp weight and the
Load
basic empty weight.
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1 July 1979
CESSNA
SECTION 1
MODEL 172RG
GENERAL
Maximum
Maximum Ramp Weight is the maximum weight approved
Ramp
for ground maneuver. (It includes the weight of start, taxi
Weight
and runup fuel.)
Maximum
Maximum Takeoff Weight
is the maximum weight
Takeoff
Weight
approved for the start of the takeoff run.
Maximum
Maximum Landing Weight is the maximum weight
Landing
Weight
approved for the landing touchdown.
Tare
Tare is the weight of chocks, blocks, stands, etc. used when
weighing an airplane, and is included in the scale read-
ings. Tare is deducted from the scale reading to obtain the
actual (net) airplane weight.
1 July 1979
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