To determine the amount of ballast needed, use the formula  in  Figure 7-13 . If an airplane with an empty weight of 1,876 pounds has been  altered so its EWCG is +32.2, and CG range for weights up  to 2,250 pounds is +33.0 to +46.0, permanent ballast must be  installed to move the EWCG from +32.2 to +33.0. There is  a bulkhead at fuselage station 228 strong enough to support  the ballast. Two things must first be known to determine the amount of  ballast needed to bring the CG within limits: the amount the  CG is out of limits, and the distance between the location of  the ballast and the limit that is affected. If a repair or alteration causes the aircraft CG to fall outside  of its limit, permanent ballast can be installed. Usually  permanent ballast is made of blocks of lead painted red and  marked “Permanent Ballast—Do Not Remove.” It should be  attached to the structure so that it does not interfere with any  control action and attached rigidly enough that it cannot be  dislodged by any flight maneuvers or rough landing A block of lead weighing 7.7 pounds, attached to the bulkhead  at fuselage station 228, moves the EWCG back to its proper  forward limit of +33. This block should be painted red and  marked “Permanent Ballast—Do Not Remove.” The CG of a loaded airplane can be moved into its allowable  rangeby shifting passengers or cargo or by adding temporary  ballast. Temporary Ballast Formula Temporary Ballast Ballast needed = 1.876 × 0.8 228 – 33 = 1500.8  195 = 7.7 pounds Figure 7-13.  Formula for determining ballast. Ballast weight Aircraft empty weight  ×  Dist. out of limits Distance between ballast and desired CG = Temporary ballast, in the form of lead bars or heavy canvas  bags of sand or lead shot, is often carried in the baggage  compartments to adjust the balance for certain flight  conditions. The bags are marked “Ballast XX Pounds— Removal Requires Weight and Balance Check.” Temporary  ballast must be secured so it cannot shift its location in flight and the structural limits of the baggage compartment must not  be exceeded. All temporary ballast must be removed before  the aircraft is weighed. Permanent Ballast