GENERAL MAINTENANCE PROCEDURES

TM 10-1670-299-20&P TO 14D1-2-470-2 NAVAIR 13-1-41 2-13. GENERAL MAINTENANCE PROCEDURES. Maintenance and repair procedures being applied to the Personnel Troop Parachute System Ancillary Equipment will be limited to those authorized in the Maintenance Allocation Chart (MAC), Appendix B. The following general maintenance procedures apply: a. Darning and Patching. There is no limit to the number of darns that may be applied as long as the overall strength of the fabric is not significantly reduced. Darning and patching shall be accomplished as outlined in the appropriate procedures. Holes or tears that exceed 1-inch in length or 1-inch in diameter will not be machined or hand darned. However, any cut or tear may be repaired without zigzag stitching, provided no adjacent material is missing or damaged. Holes and tears larger than 1-inch in length or 1-inch in diameter will be patched. b. Stitching. Stitching and restitching of Personnel Troop Parachute Ancillary Equipment will be accomplished with thread that matches the color of the original stitching if possible. All straight stitching will be backed by back stitching at least 1/2-inch. Restitching will be locked by overstitching each end of the stitch formation by 1/2-inch. Zigzag stitching does not require locking; however, zigzag restitching will extend at least 1/2-inch into undamaged stitching at each end, when possible. Keep proper thread tension to prevent loose top or bobbin thread, and excessively tight stitching resulting in puckering of the materials sewn. The stitching lock shall be imbedded in the center of the material. Restitching will be made directly over the original stitching, following the original stitch pattern as closely as possible. See Table 2-3, Stitching Specifications. c. Cleaning and deburring metal items. Remove burrs, rough spots, rust, or corrosion from metal items by either filing with a metal file, or buffing with a crocus cloth. d. Searing and waxing. When specified in the separate repair procedures, nylon based fabrics will be heat seared or immersed in melted wax to prevent fraying or unraveling. Proceed as follows: CAUTION Cotton based fabrics or cord will not be heat sealed. These fabrics burn rather than melt. Serious material damage will result. (1) Searing. The ends of nylon tape, webbing, and cord lengths will be prepared by heat searing. This is accomplished by pressing the raw end of the fabric against a hot metal surface until the nylon material has melted and formed a seal. Avoid creating sharp ends or material lumping at the end. 2-33