MIL-STD-849 Inspection Requirements, Definitions And Classification Of Defects For ParachutesThis standard establishes the inspection requirements and a standard classification of manufacturing and final assembly defects for parachutes.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 - 47 - 48 - 49 - 50 - 51 - 52 - 53 - 54 - 55 - 56 - 57 - 58 - 59 - 60 - 61 - 62 - 63 - 64 - 65 - 66 - 67 - 68 - 69 - 70 - 71 - 72 - 73 - 74 - 75 - 76 - 77 - 78 - 79 - 80 - 81 - 82 - 83

MIL-STD-849B

3.2.122 Trailing edge seams. The seams sewn on the trailing edge in the spanwise direction on gliding type parachutes.

3.2.123 Upper cascade. Any junction of control lines before the lower cascade.

3.2.124 Vent. The opening at the top of a parachute canopy, generally referring to round type parachutes.

3.3 Specific definitions of parachute hardware terms and conditions.

3.3.1 Bend test. A prescribed method used to test ripcord pins for rigidity.

3.3.2 Crack. A clear crystalline break caused by localized stresses exceeding the rupture strength.

3.3.3 Hardness. The resistance to indentation or an indirect measure of tensile strength.

3.3.4 Laps. Folds in hot metal that have been rolled or forged into the surface but not welded to it.

3.3.5 Seam. An opening on the surface of metal that has been closed but not welded.

3.3.6 Soldering. The use of low melting point alloys to join metal parts.

3.3.7 Swaging. The joining of metal parts by pressure, such as in attaching ripcord locking pins to ripcord cable.

3.4 Specific definitions of parachute sewing terms and conditions.

3.4.1 Backstitch or backtack. The finishing of a row of stitching by sewing back over the origina1 stitching a short distance to retard raveling.

stress.

3.4.2

Bartack. A concentrated series of zigzag-like stitches used to reinforce points of

3.4.3

Basting. A temporary stitching, usually with long loose stitches.

3.4.4

Broken stitch. A break in sewing thread.

3.4.5

Bunched stitching. Stitches too close or more stitches per inch than required.

3.4.6

Cross box. A sewing pattern that consists of a stitched box with an X sewn from

corner to corner, usually at the end of a row of stitching to reinforce the seam.

3.4.7 Double W or 4-point. A sewing pattern that consists of two parallel rows of stitching with three equally spaced points between the parallel rows forming a double W or 4-point.