Temporary holding before final stitching is the purpose of baste work when attaching a reinforcement patch. Baste stitches are long, easily removable stitches that keep the patch in the exact position during sewing, especially on curved or bulky areas. They prevent shifting as you work and help with alignment, so the final seam sits correctly. After the permanent stitches are in place, the baste stitches are removed. It isn’t meant to permanently secure the patch, nor to resize it, nor as the primary method of marking alignment.

The key idea is to assess whether a patch can restore the required strength and reliability without compromising the parachute’s load paths, using only approved methods. The size and location of the damage determine if the patch can cover it without creating stress concentrations or interfering with reinforcements. The fabric condition around the damage matters too; if the surrounding material is worn or delaminated, a patch won’t fix the underlying problem and replacement may be needed. How the patch affects the load path is central—the repair must maintain or reproduce the intended transfer of loads through the fabric, seams, and reinforcements, not weaken them. Finally, only approved repair methods may be used; if there isn’t an approved method for that damage type or location, the repair isn’t permitted and replacement becomes necessary. Cosmetic factors like patch color or thread type don’t influence structural safety. Time of day or weather during the repair isn’t part of the decision, though safe working conditions are always important. Cost or availability of replacement patches can affect scheduling, but they don’t override the engineering and regulatory criteria for whether a repair is SAMPLEallowable.

In a galvanic couple, two dissimilar metals in an electrolyte form an electrochemical cell where electrons flow from the more active metal to the less active one. The more active metal loses electrons and oxidizes, becoming the anode and corroding. The less active metal accepts electrons and undergoes reduction, acting as the cathode and being protected from corrosion. Because corrosion is driven by oxidation, the metal that corrodes less readily is the cathode. For example, zinc will corrode as the anode when paired with copper, while copper serves as the cathode and remains comparatively protected. The other terms describe forms of corrosion rather than the role of an electrode in the galvanic couple.

NAV maintenance records use the OPNAV 4790 series, with specific form numbers assigned to each document. The Visual Inspection Data Sheet / Maintenance Action Form (VIDS/MAF) is designated on the official schedule as OPNAV 4790/60. This form is the standard record for capturing inspection results and the maintenance actions that follow, ensuring a traceable history for the equipment. The other numbers belong to different maintenance documents and are not used for VIDS/MAF, so they wouldn’t be the correct reference for this form.