MOONEY
M20TN - MODEL TYPE-S
SECTION I
GENERAL
1 -- 11
ORIGINAL ISSUE -- 04-02-2008
AIRPLANE FLIGHT MANUAL
WEIGHT AND BALANCE TERMINOLOGY
Arm
The horizontal distance from the reference datum to the center of gravity
(C.G.) of an item.
Basic
Empty
weight
The actual weight of the airplane and includes all operating equipment (in-
cluding optional equipment) that has a fixed location and is actually
installed in the aircraft.
It includes the weight of unusable fuel and full oil.
Center of
Gravity
(C.G.)
The point at which an airplane would balance if suspended. Its distance
from the reference datum is found by dividing the total moment by the total
weight of the airplane.
C.G. Arm
The arm obtained by adding the airplane’s individual moments and divid-
ing the sum by the total weight.
C.G. in
% MAC
Center of Gravity expressed in percent of mean aerodynamic chord
(MAC).
C.G.
Limits
The extreme center of gravity locations within which the airplane must be
operated at a given weight.
MAC
Mean Aerodynamic Chord.
Maximum
Weight
The maximum authorized weight of the aircraft and its contents as listed in
the aircraft specifications.
Maximum
Landing
Weight
The maximum authorized weight of the aircraft and its contents when a
normal landing is to be made.
Moment
The product of the weight of an item multiplied by its arm. (Moment divided
by a constant is used to simplify balance calculations by reducing the num-
ber of digits).
Reference
Datum
An imaginary vertical plane from which all horizontal distances are mea-
sured for balance purposes.
Station
A location along the airplane fuselage usually given in terms of distance
from the reference datum.
Tare
The weight of chocks, blocks, stands, etc. used when weighing an air-
plane, and is included in the scale readings. Tare is deducted from the
scale reading to obtain the actual (net) airplane weight.
Unusable
Fuel
Fuel remaining after a run--out test has been completed in accordance
with Federal regulations.
Usable
Fuel
Usable Fuel available for aircraft engine combustion.
Useful
Load
The basic empty weight subtracted from the maximum weight of the air-
craft. This load consists of the pilot, crew (if applicable), useable fuel, pas-
sengers, and baggage.
