MIL-DTL-9401C
3.3.10 Repairs.
3.3.10.1 Broken or skipped stitches. Broken or skipped stitches in stitch type 301 shall be
repaired by adjacent stitching with the stitches extending a minimum of 3 inches (± 1 inch)
beyond the ends of the stitches being repaired. Broken or skipped stitches in stitch type 304 or
308 shall be repaired by adjacent stitching with the stitches extending a minimum of three
stitches beyond the ends of the stitches being repaired. Broken or skipped stitches in stitch type
401 shall be repaired with stitch type 301 and as specified for broken or skipped stitches in stitch
type 301. The frequency of the stitching repairs shall not exceed the number specified in table II.
3.3.10.2 Run-offs. A run-off shall be repaired by stitching within the seam margin tolerance
with the stitches extending a minimum of 1 inch or three stitches, as applicable to the type of
stitch, from the start and the end of the run-off.
3.3.10.3 Less than specified number of stitches per inch. Where the number of stitches per inch
is less than the number specified, repairs shall be made by adjacent stitching, with the repair
extending either 1 inch or three stitches, as applicable to the type of stitch, beyond the end of the
repair.
3.3.10.4 Loose stitches. Loose stitching shall not be removed but shall be reinforced by adjacent
stitching. Loose stitches shall be interpreted as those that do not lie smoothly on the fabric when
the seam is put under tension.
3.3.10.5 Tight stitches. Tight stitches shall be removed and the section shall be restitched.
Tight stitches shall be interpreted as those that cause the fabric under the stitches to gather or
pucker when the seam is put under tension.
3.3.11 Darning tears and cuts. Darning shall be held to a minimum. Holes (see 6.4) not
exceeding ¼ inch in diameter and linear tears or cuts not exceeding ½ inch may be darned. The
darned area of linear tears or cuts shall form a rectangular pattern extending ¼ inch beyond each
side and each end of the cut or tear. All darns shall be neat and flat and shall not pucker the
canopy cloth. The darning thread shall be size A thread or yarns from the canopy and shall
match the canopy cloth.
3.3.12 Measuring operations.
3.3.12.1 Cloth. All cloth shall be measured and cut while under substantially no tension.
Tightly rolled material shall be relaxed by unrolling and, if necessary, relaxing it for 24 hours to
permit the material to return to its original state. Section pattern shall be carefully placed on the
cloth so that the small inequities of various cloth widths (within the tolerance specified) are
evenly distributed on each side of the pattern. When multiple layers of cloth are cut at the same
time, extreme care shall be taken to prevent the cloth from slipping during any part of the cutting
operation.
3.3.12.2 Suspension and vent lines. The suspension and vent lines shall be measured under the
tension specified in table III and marked to show the points of attachment to the drag surface and
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