Item Weight Arm Moment
Aircraft Empty Weight 2,100 78.3 164,430
Front Seat Occupants 340 85.0 28,900
Rear Seat Occupants 350 121.0 42,350
Fuel 450 75.0 33,750
Baggage Area 1 80 150.0 12,000
Total 3,320 281,430
281,430 ÷ 3,320 = 84.8
Figure 10-5. Example of weight and balance computations.
Sample Loading Problem Weight (lb) Moment
(in-lb/1,000)
1. Basic empty weight (Use data pertaining
to aircraft as it is presently equipped)
includes unusable fuel and full oil
2. Usable fuel (At 6 lb/gal)
Standard tanks (40 gal maximum)
Long range tanks (50 gal maximum)
Integral tanks (62 gal maximum)
Integral reduced fuel (42 gal)
3. Pilot and front passenger (Station 34
to 46)
4. Rear passengers
5. Baggage area 1 or passenger on child’s
seat (Station 82 to 108, 120 lb maximum)
6. Baggage area 2
(Station 108 to 142, 50 lb maximum)
7. Weight and moment
1,467 57.3
240 11.5
340 12.7
300 21.8
20 1.9
2,367 105.2
Figure 10-6. Weight and balance data.
weight and balance distribution prior to takeoff are runway
length, runway surface, runway slope, surface wind, and the
presence of obstacles. These factors may require a reduction
in or redistribution of weight prior to flight.
Some aircraft are designed so that it is difficult to load them
in a manner that places the CG out of limits. These are
usually small aircraft with the seats, fuel, and baggage areas
located near the CG limit. Pilots must be aware that while
within CG limits these aircraft can be overloaded in weight.
Other aircraft can be loaded in such a manner that they will
be out of CG limits even though the useful load has not been
exceeded. Because of the effects of an out-of-balance or
overweight condition, a pilot should always be sure that an
aircraft is properly loaded.
Determining Loaded Weight and CG
There are various methods for determining the loaded weight
and CG of an aircraft. There is the computational method as
well as methods that utilize graphs and tables provided by
the aircraft manufacturer.
Computational Method
The following is an example of the computational method
involving the application of basic math functions.
Aircraft Allowances:
Maximum gross weight......................3,400 pounds
CG range.............................................78–86 inches
Given:
Weight of front seat occupants.............340 pounds
Weight of rear seat occupants..............350 pounds
Fuel...........................................................75 gallons
Weight of baggage in area 1....................80 pounds
1. List the weight of the aircraft, occupants, fuel, and
baggage. Remember that aviation gas (AVGAS)
weighs 6 pounds per gallon and is used in this
example.
2. Enter the moment for each item listed. Remember
“weight x arm = moment.”
3. Find the total weight and total moment.
4. To determine the CG, divide the total moment by the
total weight.
NOTE: The weight and balance records for a particular
aircraft provide the empty weight and moment, as well as the
information on the arm distance. [Figure 10-5]
The total loaded weight of 3,320 pounds does not exceed
the maximum gross weight of 3,400 pounds, and the CG of
84.8 is within the 78–86 inch range; therefore, the aircraft is
loaded within limits.
Graph Method
Another method for determining the loaded weight and CG is
the use of graphs provided by the manufacturers. To simplify
calculations, the moment may sometimes be divided by 100,
1,000, or 10,000. [Figures 10-6, 10-7, and 10-8]
Front seat occupants....................................340 pounds
Rear seat occupants ......................................300 pounds
Fuel .................................................................40 gallons
Baggage area 1 ...............................................20 pounds
The same steps should be followed in the graph method as
were used in the computational method except the graphs
provided will calculate the moments and allow the pilot to
determine if the aircraft is loaded within limits. To determine
the moment using the loading graph, find the weight and draw
a line straight across until it intercepts the item for which the
moment is to be calculated. Then draw a line straight down
to determine the moment. (The red line on the loading graph
in Figure 10-7 represents the moment for the pilot and front
passenger. All other moments were determined the same
400
350
300
250
200
150
100
50
0 5 10 15 20 25 30
340
12.7
0 50 100 150 200 250 300 350 400
Load Moment/1,000 (kilogram-millimeters)
0
25
50
75
100
125
150
175
200
Load Weight (kilograms)
Load Moment/1,000 (inch-pounds)
Load Weight (pounds)
Maximum Usable Fuel
* Standard tanks
** Long range tanks
*** Internal tanks
Pilot & front passenger
Rear passengers
Baggage area 1 or
passenger on child’s seat
Fuel (6 lb/gal; 0.72 kg/liter)
62 gal***(234.7 liters)
Baggage area 2
60 gal (227.1 liters)
50 gal**(189.3 liters)
42 gal reduced***(159 liters)
40 gal*(189.3 liters)
30 gal (113.6 liters)
20 gal (75.7 liters)
10 gal (37.9 liters)
2,400
2,300
2,200
2,100
2,000
1,900
1,800
1,700
1,600
1,500
45 50 55 60 65 70 75 80 85 90 95 100 105 110
2,367
105.2
Loaded Aircraft Moment/1,000 (kilogram-millimeters)
700
750
800
850
900
950
1,000
1,050
1,100
Loaded Airplane Weight (kilograms)
Loaded Aircraft Moment/1,000 (inch-pounds)
Loaded Aircraft Weight (pounds)
600 700 800 900 1,000 1,100 1,200 1,300
Utility category
Normal
category
Figure 10-8. CG moment envelope.
Figure 10-7. Loading graph.