SECTION 1
CESSNA
GENERAL
MODEL 172S NAV III
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 reducing 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
(C.G.)
from 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
Arm
adding the airplane's individual moments and dividing
the sum by the total weight.
C.G.
Center of Gravity Limits are the extreme center of
Limits
gravity locations within which the airplane must be
operated at a given weight.
Standard
Standard Empty Weight is the weight of a standard
Empty
airplane, including unusable fuel, full operating fluids
Weight
and full engine oil.
Basic Empty Basic Empty Weight is the standard empty weight
Weight
plus the weight of optional equipment.
Useful Load
Useful Load is the difference between ramp weight
and the basic empty weight.
(Continued Next Page)
1-12 U.S.
172SPHAUS-00
