Figure 7-7. Moments for fuel, pilot, and passenger. 

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4
 

After recording the basic empty weight and moment of
the helicopter, and the weight and moment for each item, total and record all weights and moments. Next, plot the calculated takeoff weight and moment on the sample moment envelope graph. Based on a weight of 1,653 pounds and a moment/1,000 of 162 pound-inches, the helicopter is within the prescribed CG limits.
COMBINATION METHOD
The combination method usually uses the computation method to determine the moments and center of gravity. Then, these figures are plotted on a graph to determine if they intersect within the acceptable envelope. Figure 7-9 illustrates that with a total weight of 2,399 pounds and a total moment of 225,022 pound

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100 200 300 400 500 LOAD WEIGHT (LBS)
 

Start at the bottom scale labeled LOAD WEIGHT. Draw a line from 211 pounds up to the line labeled “FUEL @ STA108.5.” Draw your line to the left to intersect the MOMENT scale and read the fuel moment
(22.9 thousand lb.-inches). Do the same for the pilot/passenger moment. Draw a line from a weight of 340 pounds up to the line labeled “PILOT & PASSENGER inches, the CG is 93.8. Plotting this CG against the weight indicates that the helicopter is loaded within the longitudinal limits (point A).
  Longitudinal   2,500� 2,300� 2,100� 1,900� 1,700� 1,500 CL 91 93 95 97 99 101 103 260 256 252 248 244 240 236 232 1,100� 1,050� 1,000� 950� 900� 850� 800� 750� 700 Fuselage Station (CM from Datum) Gross Weight lb. Gross Weight KG Fuselage Station (in. from Datum) Main� Rotor Most Fwd� CG with� Full Fuel Longitudinal (Point A)
 Weight  (pounds)  Arm  (inches)    Moment� (lb/inches)
Basic Empty Weight�  1,400�  107.75�    150,850�
Pilot�  170�  49.5�    8,415�
Fwd Passenger�  250�  49.5�    12,375�
Right Fwd Baggage�  �  44�    0
Left Fwd Baggage�   44�    0
Right Aft Passenger�   79.5�    0
Left Aft Passenger�  185�  79.5�    14,708�
Right Aft Baggage�  50�  79.5�    3,975�
Left Aft Baggage�  50�  79.5�    3,975�