7-3 Weight and Balance Revision Record Major Alteration and Repair Aircraft manufacturers use different formats for their weight  and balance data, but  Figure 7-3  is typical of a weight and  balance revision record. All weight and balance records  should be kept with the other aircraft records. Each revision  record should be identified by the date, the aircraft make,  model, and serial number. The pages should be signed by  the person making the revision and his or her certificate type  and number must be included. The computations for a weight and balance revision  are included on a weight and balance revision form.  Appropriate fore-and-aft extreme loading conditions should  be investigated and the computations shown. The date those  computations were made is shown in the upper right corner  of  Figure 7-3 . When this work is superseded, a notation  must be made on the new weight and balance revision form,  including a statement that the new computations supersede  the computations dated “MM/DD/YY.” Any major alteration or repair requires the work to be done  by an FAA-certificated mechanic or repairman or facility.  The work must be checked for conformity to FAA-approved  data and signed off by an aircraft mechanic holding Inspection Authorization (IA) or by an authorized agent of  an appropriately rated FAA-approved repair station. A Repair  Station record and/or FAA form 337, Major Repair and  Alteration, must be completed describing the work. (Reference  Title 14 of the Code of Federal Regulations (14 CFR) part 43,  appendix B, for the recording of major repair and alterations  requirements.) A dated and signed revision to the weight and  balance record is made and kept with the maintenance records,  and the airplane’s new empty weight and empty weight arm  or moment index are entered in the POH/AFM. Within the following text, information concerning major  repairs or major alterations does not apply to any aircraft  within the light-sport category. This category of aircraft is  not eligible for major repairs or alterations. Figure 7-2.  Typical comprehensive equipment list. * Indicates total weight/arm for all subcomponents