TM 1-1500-204-23-1 c.  Upholstered  Seats. Cleaning, repair, and instal- lation and removal procedures are explained in ‘the fol- lowing paragraphs. (1) Cleaning. Clean upholstered seats by using cleaning materials and methods as prescribed in para- graph 9-20a. (2)  Repair. Repair small rips or tears with a sewed or unsewed patch. Attach unsewed patches with adhesive, Federal Specification MMM-A-1617. (3) Installation and removal. For instructions installation and removal, refer to the applicable mainte- nance manual for particular aircraft. d. Raschel Knit Seat Covers. Raschel knit seat cover maintenance limits are listed below: Deterioration or discoloration which indicates a strength decrease to the point where it affects the integrity of the seat(s) is not allowed. Tears,  cuts,  or  holes  greater  than  2.5  inch  in  length or diameter are not allowed; the seat should be replaced Tears, cuts, or holes less than 2.5 inch in length can be repaired. Repair is not allowed for seat covers with  holes,  cuts,  or  tears  in  raschel  kit  material  that are located close to the seams of the adjoining panels and do not allow sufficient space for the darning procedure. Repair should be used as a temporary measure until new seat covers or back covers  can  be  installed.  In  the  fine-mesh  duck  cloth surrounding  the  raschel  knit  material,  tears,  cuts and  holes  up  to  2.5  inches  in  length  can  be repaired.  A  different  method  for  repairing  is required and is as follows: Tears, cuts or holes less than 0.5 inch in length may be  repaired  by  stitching  which  extends  0.5  inch  into the  sound  material  surrounding  the  damaged  area. Tears,  cuts  or  holes  of  up  to  1.0  inch  in  length  may be repaired with the use of a patch made of the same material as the seat cover. Locate on the underside of the damaged area and sew a zigzag stitch over the tear area and into patch extending 0.5 inch into the sound material surrounding the damaged area. Tears, cuts, or holes of 1.0 to 2.5 inches in length may be repaired with the use of a patch made of the same  material  as  the  seat  cover.  The  patch  should be sized to extend 1.0 inch in all directions to the damaged area and include 0.50 inch of material to fold under to finish all the edges of the patch. The patch should be located on the underside of the damage area with the folded edges to the inside. Zig-zag sew the damage area into the patch, fol- lowed by a minimum of two (2) rows of stitching around the patch using 6-9 stitches per inch. NOTE A  24  month  service  life  pertains  only  to  those covers which are used in an energy attenua- tion application. Replace the original nylon spall shield, or use new ballistic nylon MIL-C-12369 for replacement. Apply a thin even coat of contact adhesive EC 1300L (FSCM 04963) to the tile surface. Allow adhesive to dry until tacky. Carefully mate the spall shield to the tile, working it on by hand pressure. Fit the nylon snugly over the fiberglass patch (or patches). Do not wrap the spall shield over the edge of the panel. Tears in the spall shield shall not exceed 3 inches. Any unbonded area of the spall shield, (as evidenced by bulges), shall not exceed a diameter of 1 inch. Seat covers made of raschel knit nylon cloth shall have a service life of 24 months. Seat covers that are not marked with an installation date shall be assumed to have the same date as the day of acceptance of the aircraft. Replacement covers shall be marked with contrasting ink conforming to MIL-l-6903. The size of marking shall be of sufficient size and location so that it can easily be read. The following is an example of marking installation date: 7 Mar 88 e.  Polyester  Fabric  Seat  Covers  (Uh-60). Clean- ing, repair, and installation and removal procedures for polyester fabric seat covers are explained in the following paragraphs. (1) Cleaning. Clean  the  polyester  fabric  seat and back using the following procedures: (a)  Brush  fabric  with  firm  bristle  brush removing excess dirt. (b)  Use  enough  liquidto  allow  complete immersion of the seat cover to be washed. (c) Mix 3 ounces of low strength laundry soap, Federal Specification P-S-1792, to each gallon of water. Synthetic detergentis permissible as an alterna- tive. 9-44 Change 2