Technical data

1.4.Detecting the center of gravity position, allowed and measured values
Observance of the center of gravity is decisive for the stability and manageability of the
airplane. That´s why it is necessary for every airplane holder to know how to diagnose the
center gravity position of the airplane for factual occupancy.
It is necessary to know the length of the middle aerodynamic subtence when making the
calculation of the center of gravity. Calculated center of gravity must be inside the range
given by the producer.
Length of middle aerodynamic subtance of the wing 1420mm
Allowed range of the center of gravity in %SAT 22-28
When detecting the point of balance and subsequent calculation let the airplane stand in
flying position at three weighting-machines and proceed after these instructions:
1.4.1.Weighing the airplane for the headmost center of gravity position
-pilot´s seat is occupied with a pilot with the lowest allowed weight
-there can not be any load on the plane, the fuel tank must be empty
-at the weighing-machines under the main undercarriage deduct the data of the weighing-
machines, the weight effecting to the main wheels Gp you can find out as the sum of the data
of both weighing-machines
-deduct the weight effecting the front wheel Go at the weighing machine under the front
wheel
-total weight of the airplane Gvzl. is equal to the sum of Gp+Go
-measure the distance of axle of the main undercarriage from the axle of the front wheel Lb
in millimeters
-measure the distance of leading edge of the wing / with plummet/ from the axle of the main
undercarriage La in millimeters
-measure the vertical distance of the point of balance from the axle of main undercarriage Lt
by the formula : Lt=Go*Lb/Gvzl
-measure the distance of the point of balance from the leading edge of the wing Xt by the
formula: Xt=La-Lt
-calculate the front center of gravity in percents by the formula X%=Xt/SAT*100
1.4.2.Weighing the airplane for the backmost center of gravity
Pilot´s seat and the seat next to the pilot must be occupied with maximum weight of the crew,
also the fuel tank must be full and the useful load must have the maximum weight.
The procedure of measuring and weighing is the same as detecting the front center of gravity
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