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.  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.  The following is an example of the computational method  involving the application of basic math functions.  Aircraft Allowances:  Given:  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  4. To determine the CG, divide the total moment by the  total weight.  3. Find the total weight and total moment.  2. Enter the moment for each item listed. Remember  “weight  x  arm = moment.”  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.  Figure 10-6.  Weight and balance data.  10-7  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  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]  84.8 is within the 78–86 inch range; therefore, the aircraft is  loaded within limits.  Figure 10-5.  Example of weight and balance computations.  Graph Method  Determining Loaded Weight and CG  Computational Method  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  Maximum gross weight......................3,400 pounds  CG range.............................................78–86 inches  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  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 Front seat occupants....................................340 pounds Rear seat occupants ......................................300 pounds Fuel.................................................................40 gallons Baggage area 1 ...............................................20 pounds