Attachment_0002_-_MIL-STD-849C.pdf

AMSC N/A FSC 1670

INCH-POUND

MIL-STD-849C

31 July 2009

SUPERSEDING

MIL-STD-849B

25 July 2001

DEPARTMENT OF DEFENSE

STANDARD PRACTICE

INSPECTION REQUIREMENTS, DEFINITIONS

AND CLASSIFICATION OF DEFECTS

FOR PARACHUTES

Comments, suggestions or questions on this document should be addressed to: Defense Supply Center Richmond, ATTN: DSCR-VEB, 8000 Jefferson Davis Highway, Richmond VA 23297. Since contact information can change, you may want to verify the currency of this address information using the ASSIST database at http://assist.daps.dla.mil.

Downloaded from http://www.everyspec.com ii

CONTENTS

PARAGRAPH PAGE

1. SCOPE

1.1 Scope

1.2 Purpose

1.3 Application

2. APPLICABLE DOCUMENTS

2.1 General

2.2 Non-Government publications

2.3 Order of precedence

3. DEFINITIONS

3.1 General definitions

3.2 Specific definitions of parachute terms

3.3 Specific definitions of parachute hardware terms and conditions

3.4 Specific definitions of parachute sewing terms and conditions

4. GENERAL REQUIREMENTS

4.1 Limitation of use

4.2 Interpretation of classification of defect tables

5. DETAIL REQUIREMENTS

5.1 Inspections and tests

5.1.1 Component and material inspection

5.1.2 In-process inspection of the product

5.1.3 Final inspection of the product

6. NOTES

6.1 Intended use

6.2 Past usage

6.3 Subject term (key word) listing

6.4 Changes from previous issue

iii

CONTENTS

TABLE PAGE

I Personnel parachutes – guideline for maximum allowable errors per canopy II Cargo, deceleration, extraction, recovery, special weapon and low cost parachute systems and containers – guideline for maximum allowable errors per canopy III Classification of defects – solid and extended skirt parachute canopies – personnel IV Classification of defects – ring slot and ribbon parachute canopies V Classification of defects – pilot chutes and drogues VI Classification of defects – personnel parachute packs or containers, and deployment bags VII Classification of defects – personnel parachute harnesses, risers, static lines, bridle lines, straps, lanyards, and pockets VIII Classification of defects – deployment bags and packs (other than personnel) IX Classification of defects – risers, static lines, bridles, straps, adapter webs, and retainers (other than personnel) X Classification of defects – personnel parachute, integrated pack and harness XI Classification of defects – canopies: square, gliding type – main and reserve XII Classification of defects – Classification of defects – pilot chutes for MC-4 and

MIRPS and spring assembly, ejector only………………………………………..…57 XIII Classification of defects – integrated pack and container (without harness), deployment bag and pocket – MC-4 only XIV Classification of defects – harness, riser, bridle line, strap, and lanyard – MC-4 only XV Classification of defects – solid and extended skirt parachute canopies – cargo XVI Classification of defects – low cost aerial delivery system (LCADS): High

Velocity (HV), Spider Parachute……………………………………………………………

XVII Classification of defects – low cost aerial delivery system (LCADS): Low Velocity (LV) BAT Parachute……………………………………………………………

XVIII Classification of defects – low cost low altitude aerial delivery system (LCLA):

Stalker, Cross Parachute System Assembly………………………………………… 77

XIX Classification of defects - Low Cost Container (LCC)……………………………...79

l. SCOPE

1.1 Scope. This standard establishes the inspection requirements and a standard classification of manufacturing and final assembly defects for parachutes.

1.2 Purpose. The purpose of this standard is to:

a. Provide a uniform standard of quality for determining the acceptability of parachutes and their components.

b. Standardize the inspection requirements for all parachute manufacturers.

c. Consolidate, into a single document, definitions of all parachute terms.

1.3 Application. This standard should apply when it is referenced in the specification or contract provisions.

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in the tables of this standard. This section does not include documents cited in other sections of this standard or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements documents cited in sections 3, 4, and 5 of this standard, as well as those cited in the tables, whether or not they are listed.

2.2 Non-Government publications. The following document forms a part of this document to the extent specified herein. Unless otherwise specified, the issue of this document is the issue cited in the solicitation or contract.

AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM)

ASTM D 6193 Standard Practice for Stitches and Seams

(DoD adopted).

(Copies of this document are available online at http://www.astm.org/ or from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959.)

2.3 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict between the text of this standard and the reference cited herein, the text of this standard takes precedence. Nothing in this standard, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.

3. DEFINITIONS

3.1 General definitions. The following are the definitions for the two classifications of defects used in this standard. Note that some definitions may apply primarily to only round/ballistic type parachutes or only to gliding/ram-air type parachutes or to both.

3.1.1 Major/Critical defect. A defect that is likely to result in failure or to reduce the usability of the unit of product for its intended purpose. A major/critical defect is also defined as a dimension out of tolerance, component and or construction deviation which may adversely affect the fit, form or function of the parachute assembly.

3.1.2 Minor defect. A defect that is not likely to reduce the usability of the unit of product for its intended purpose or is a departure from established standards having little bearing on the effective use or the operation of the unit.

3.2 Specific definitions of parachute terms.

3.2.1 Adapter. A rectangular metal fitting with a crossbar incorporated in a parachute harness to permit proper adjustment of harness.

3.2.2 Adapter, harness quick fit. An adapter in which a floating friction grip is used in lieu of a fixed crossbar.

3.2.3 Apex. The center and top most point of an inflated round parachute canopy.

3.2.4 Back pad. A pad attached to the inside of the harness to provide comfort for the wearer and help keep the harness in place.

3.2.5 Back strap. Part of the harness webbing extending across the back of the wearer.

It may or may not be adjustable.

3.2.6 Bag, deployment. A type of container made of fabric and webbings in which a parachute canopy is packed.

3.2.7 Band, lateral. Webbing inserted in the hem of parachute canopies to reinforce edges of fabric and distribute the load. The lower lateral band is inserted in the skirt hem and the upper lateral band is inserted in the vent hem.

3.2.8 Band, pocket. A piece of textile tape or line attached at the outside of the skirt across main seams in such a manner as to cause the gores to be pulled outward at inflation.

3.2.9 Band, reinforcement. A tape or a ribbon inserted in various positions to reinforce weak points in a canopy.

3.2.10 Band, retainer. A rubber band used to hold folded suspension lines or static lines to deployment bags or parachute packs.

3.2.11 Bias. A cut or seam running obliquely across the threads of a fabric.

3.2.12 Binding. A piece of tape or fabric folded over and stitched to a raw edge of the fabric to prevent raveling or fraying.

3.2.13 Bottom, false. A piece of fabric sewed to the inside of a pack to retain the frame;

it also serves as a base for stitching the suspension line retaining loops.

3.2.14 Breakcord. A thread or tape tied between parachute components that is intended to break under desired load during deployment.

3.2.15 Bridle. The cord attaching the pilot chute to the vent of a parachute canopy or to the deployment bag.

3.2.16 Burns, friction. Result of rapid rubbing together of two textile surfaces, generating frictional heat, which reduces tensile strength of the textile and causes the deterioration of individual threads.

3.2.17 Cable, ripcord. A flexible cable, usually made of corrosion resistant steel, joining the locking pins and the ripcord grip.

3.2.18 Canopy. The portion of a parachute consisting of the drag-producing surface and the suspension lines extended to one or more mutual confluence points.

3.2.18.1 Canopy, extended skirt. A canopy made from cloth having a flat circular center to which an annular ring is added.

3.2.18.2 Canopy, flat circular. A canopy made from cloth and constructed as a flat circular surface with a center orifice (vent) and consisting of a number of gores stitched together laterally, the joints forming the radial seams.

3.2.18.3 Canopy, guide surface. A canopy made from cloth similar to flat circular canopy except the alternate roof panels are extended to provide guide surfaces.

3.2.18.4 Canopy, ribbon. A canopy of flat circular design and composed of concentric cloth ribbons, supported by a number of radial ribbons and smaller supporting tapes.

3.2.18.5 Canopy, ring sail. A canopy of annular ring type developed on a spherical surface by a unique system of gore coordinates, basically shaped as a quarter sphere wherein slots in the gore are crescent shaped rather than trapezoidal (except on the crown).

3.2.18.6 Canopy, ring slot. A canopy of flat circular design made from wide concentric cloth strips with intervening air slots. The number of slots vary, depending upon canopy diameter.

3.2.19 Cap seam. The top seam of the pilot chute, which joins the gores and the duck cloth disk together.

3.2.20 Cascade. The junction of two groups of suspension lines before attachment to the risers on gliding type parachutes.

3.2.21 Cell. Two adjacent air intake passages between two adjacent groups of suspension lines on ram-air or similar gliding type parachutes.

3.2.22 Channel canopy. The space or opening through which the suspension lines are passed. It is formed by the overlapping of the fabric in the main seams, or by the addition of cover tape to the drag producing surface, generally on round type parachutes.

3.2.23 Chest protector. A pad fastened to the inside of the harness to absorb shock.

3.2.24 Chordwise. The direction in which the ribs are attached on the upper and lower glide surfaces of gliding type parachutes.

3.2.25 Chordwise seams. The seams that attach the rib panels to the upper and lower glide surfaces of gliding type parachutes.

3.2.26 Chest strap. A harness strap secured across the chest to prevent the wearer from falling out of the harness.

3.2.27 Chute. The term used interchangeably for the word "parachute."

3.2.28 Chimney effect. A change in the gradual tapering of the gores of the canopy resulting in constriction between the hem and vent.

3.2.29 Clevis. A u-shaped metal fitting with a hole in each end to receive a pin or bolt.

3.2.30 Clip, safety. A special shaped metal fitting used to prevent the accidental opening of the parachute harness release.

3.2.31 Cluster. Two or more parachutes that are attached to a single load and designed to open simultaneously.

3.2.32 Cone, pack. A small cone-shaped metal post, sewn to one of the side flaps of the pack, containing a drill hole through the cone near the top. Grommets positioned on the opposite flap of the pack are placed over the cones and ripcord pins are inserted in the cone hole to keep the pack closed.

3.2.33 Control lines. Used to steer and maneuver canopy, also known as steering or brake lines.

3.2.34 Control line, continuity. Free and clear routing to certain areas on canopy to ensure proper steering of canopy.

3.2.35 Cord, arming. The cord that pulls the firing wire out of a reefing line cutter or other actuating device, thereby arming the device.

3.2.36 Corner, flap. A rectangular tab used on packs to add protection to the canopy when packed.

3.2.37 Cross port vent holes. The vent holes cut in the rib panels of ram-air type gliding parachutes.

3.2.38 Cross seam. The sewn seam between adjacent main seams holding sections of the canopy gore together.

3.2.39 Crown. A fabric panel used to close or cover the apex vent in certain types of parachute canopies. Also may refer to the upper portion of a canopy, particularly a round type parachute.

3.2.40 Cutter, reefing line. A device designed to cut through the reefing line of a canopy, normally incorporating a delay device (mechanical or pyro-technical), a power device (mechanical or pyro-technical), and a knife-edge cutter.

3.2.41 Dart. A short tapered seam.

3.2.42 Diameter, constructed (Dc). The designation of the size of a parachute canopy, based upon design dimensions typically used for round type parachutes.

3.2.43 D-ring. An item of hardware shaped like a "D" into which connector snaps are hooked.

3.2.44 Drogue. A fabric surface shaped like a cone, more often a small first-stage parachute canopy in a system used for initial deceleration and stabilization.

3.2.45 Elastics, pack-opening. Rubber or metal springs with a means of attaching at each end, installed on the pack under tension and used to separate end flaps from side flaps when the parachute ripcord is pulled.

3.2.46 Eye. A small steel-wire loop attached to the pack, into which is fastened a hook of a pack opening elastic.

3.2.47 Eyelet. Small metal reinforcement for a hole in fabrics. It is thinner and smaller than a grommet and has no washer.

3.2.48 Flap, bag or pack. A fabric extension on a side or end of the pack designed to enclose and protect the canopy.

3.2.49 Flap, locking pin protector. A flap that covers the locking pins and cones to prevent the pack from being opened by any means other than pulling the ripcord.

3.2.50 Flaring. Method of splitting, taping, and stitching the end of webbing to widen it and prevent it from slipping through an adapter.

3.2.51 Glide surfaces, upper and lower. The spanwise panels that form the top and bottom glide surfaces of gliding type parachutes.

3.2.52 Gore. The portion of a canopy between two adjacent suspension lines or radial seams on a round type parachute.

3.2.53 Grommet. A metal eyelet and washer used as reinforcement around a hole in fabric.

3.2.54 Handle, ripcord. A loop/handle, generally of metal or rigid material, that provides a grip for pulling manual actuated ripcord cables on ripcord actuated parachutes.

3.2.55 Hardware. All metal fittings used on parachutes, parachute systems, and suspended loads.

3.2.56 Harness. An arrangement of webbings and hardware designed to conform to the shape of the load in order to secure it properly and to distribute the stress from the opening shock and the weight of the load.

3.2.57 Hem. Fabric folded back upon itself and sewn in this position to form both the peripheral edge and the vent of the canopy.

3.2.58 Hem rigged canopy. A canopy whose suspension lines are attached to the skirt hem and do not pass over the drag-producing surface, generally in reference to round type

3.2.59 Hesitator, skirt. A device that restricts the skirt of the canopy, thus preventing inflation until completion of snatch force, at which time the hesitator line breaks and allows inflation of the canopy.

3.2.60 Hook, pack opening, elastic. A small formed steel-wire device attached to each end of a pack-opening elastic that hooks into eyes sewn on the pack.

3.2.61 Housing, ripcord. A flexible metal tube in which the ripcord cable is placed.

3.2.62 Junction. The physical attachment of groups of suspension lines or control lines to each other.

3.2.63 Keeper. A length of webbing sewn on a pack or around suspension lines or risers, and adjusted to hold the pack firmly to the harness or the load on which it is used, or to form a confluence point for suspension lines or risers to prevent relative movement of lines or risers.

3.2.64 Knot, clove or half hitch. A type of knot commonly used for attaching the suspension lines of a parachute to the connector links.

3.2.65 Knot, overhand. A simple knot tied in each running end of a piece of cord above a square knot or surgeon's knot to prevent the ends from slipping back through the knot.

3.2.66 Knot, square. A strong knot for joining two cords or lines that does not slip or loosen easily.

3.2.67 Knot, surgeon's. A type of knot commonly used for tying nylon threads or cords in place of a square knot to prevent mis-tying.

3.2.68 Lanyard. A length of cord, webbing, or other material used to retain parachute subassemblies to each other or a device used to activate the deployment of a parachute system.

3.2.69 Leading edge. The front area in which the air enters the canopy, generally for gliding type parachutes but sometimes used for round type parachutes. May also refer to edge facing upstream into the airflow of a ribbon or cloth section for ribbon and ring slot parachutes.

3.2.70 Leading edge seams. The two seams sewn on the leading edge in the spanwise direction on gliding type parachutes.

3.2.71 Leg strap. The retention strap, which is part of the harness, used to secure the harness to the wearer's legs.

3.2.72 Lift web. The main harness webbing.

3.2.73 Line, guide or control. Two or more parachute lines that run from a slot or orifice in a steerable canopy to the risers. Control lines for a gliding parachute are connected from the trailing edge to a cascade and routed to the risers.

3.2.74 Line, reefing. A length of cord or line passed through rings on the skirt of the drag-producing surface to delay or control opening of the canopy.

3.2.75 Line, spreader. X pattern webbing used in the LCADS HV as a deployment aid to ensure that the suspension lines maintain continuity.

3.2.76 Line, static. A line, webbing, or cable used to open a pack or to deploy the canopy, one end of which is fastened to the pack, canopy, or deployment bag, and the other to some part of the launching vehicle.

3.2.77 Line, suspension. Cords or webbing that connect the drag-producing surface to the harness or the load.

3.2.77.1 Line, suspension, flat. A line made of tape or webbing.

3.2.78 Lines, vent. The lines that cross the vent of a canopy.

3.2.79 Line reinforcement (V tabs or butterfly). A tape wrapped tightly about the suspension line and sewn to the suspension line and skirt hem.

3.2.80 Link, connector. An item of hardware used to connect suspension lines at the load attaching point.

3.2.81 Link, connector, separable. A readily separated link to facilitate assembly of risers to suspension lines.

3.2.82 Loop, locking. A loop sewn to the deployment bag or canopy to sequence the opening of a parachute assembly.

3.2.83 Loop, retaining. A loop of webbing or tape used to hold folded lines or excess webbing in position.

3.2.84 Loop, stow. A tape, webbing, or elastic band on a pack or deployment bag that holds suspension lines in position during the packing and opening process.

3.2.85 Lower cascade. The junction of control lines closest to the risers on gliding type

3.2.86 Lug. A flat metal fitting attached to the ends of the harness webbing to provide attachment to the harness release.

3.2.87 Main seam. The seam sewn from skirt to vent holding gores together and used as a guide for the suspension line on a round type parachute.

3.2.88 Nominal tension. One percent of the minimum breaking strength of the main strength-bearing material. A maximum pull for nominal tension should be 30 pounds.

3.2.89 Pack or container. The container that encloses the canopy or deployment bag in a packed condition and which provides a means of opening to allow deployment of the canopy.

3.2.90 Pack cover. A piece of duck or canvas material with a static line attached used to cover a packed canopy.

3.2.91 Pack frame. A rigid or flexible frame used to maintain the shape of the pack.

3.2.92 Pack, opening spring, band. A cloth covered steel spring assembly with a hook at each end that rapidly pulls the flaps away from the canopy allowing quick opening of the pack.

3.2.93 Panel. The portion of a canopy between two adjacent suspension lines or radial seams.

3.2.94 Parachute. An assembly consisting of canopy, risers, bridles, deployment bag, and, in some cases, a pilot chute. Pack and attaching webbings (harnesses) are a part of the parachute when they are built into the suspended load as an integral part of the load.

3.2.94.1 Parachute, airdrop (cargo chute). A parachute designed to deliver equipment or supplies from aircraft in flight.

3.2.94.2 Parachute, approach, landing. A parachute used in flight to improve jet aircraft flight characteristics during normal landing approach or in approach under marginal weather conditions.

3.2.94.3 Parachute, back-type. A parachute designed for attachment to the wearer's back.

3.2.94.4 Parachute, chest-type. A parachute designed for attachment to the wearer's chest.

3.2.94.5 Parachute, deceleration (drag). A parachute used on jet aircraft to decrease landing roll.

3.2.94.6 Parachute, extraction. A parachute used to extract cargo from aircraft in flight and to deploy cargo parachutes.

3.2.94.7 Parachute, gliding: A parachute specifically designed to glide, generally of the ram-air type configured as a rectangular or elliptical wing, sometimes referred to as a square parachute.

3.2.94.8 Parachute, personnel. A parachute used to lower personnel from aircraft in flight.

3.2.94.9 Parachute, recovery system. Normally these systems are comprised of static lines, a pilot chute, deployment bag(s), first stage parachute (used to decelerate and stabilize the load), intermediate parachute (used to further decelerate the load), final recovery parachute (used for final delivery of load to earth), and controlling/actuating devices.

3.2.94.10 Parachute, reserve. A second parachute, usually worn on chest of personnel making a premeditated jump, to be used in the event that the main parachute fails.

3.2.94.11 Parachute, round. A parachute in a generally round configuration that has no or very minimal glide capability and is generally considered to have a ballistic trajectory. May refer to a number of round configurations or to any non-gliding configuration.

3.2.94.12 Parachute, seat-type. A parachute designed for attachment to the saddle of the harness and may serve as a seat cushion in certain types of aircraft.

3.2.94.13 Parachute, troop. A parachute used by paratroopers for a premeditated jump over a designated area.

3.2.94.14 Pilot chute. A small parachute used to accelerate deployment of the main parachute. Some pilot chutes are equipped with a metal spring device to open the canopy when released from the pack.

3.2.95 Pilot chute frame. A wire frame or spring used in the pilot chute to initiate the opening action of the chute upon release from the pack.

3.2.96 Pin, locking (ripcord). A short metal pin attached to the ripcord cable that is inserted into a pack cone or other device to secure the flaps as a function of closing a parachute pack.

3.2.97 Pocket, log record. A small patch pocket sewn to the pack or riser for carrying the parachute log record.

3.2.98 Radial seam. The seam sewn from skirt to vent holding gores together and used as a guide for the suspension lines for round type parachutes. This term is normally used in lieu of main seam for ribbon-type parachutes.

3.2.99 Reefing rings. The rings sewn to the skirt of a canopy at suspension line attaching points through which the reefing line is passed.

3.2.100 Reinforcement tapes. Any tape or webbing sewn to a pack or canopy at a point of high load to distribute the load and strengthen the fabric.

3.2.101 Release, canopy. A device that is designed to permit rapid separation of the canopy and risers from the suspended load.

3.2.102 Release, harness. A device that is designed to permit rapid release of the harness from the wearer.

3.2.103 Release, 3-ring. The rings and webbing that compose a riser/canopy release mechanism consisting of three interlocked rings of graduated size..

3.2.104 Ribs. The airfoil shaped panels that are attached to the upper and lower gliding surfaces in the chordwise direction, generally for a ram-air gliding type parachute but may refer to internal structure of some round type parachutes.

3.2.105 Rib panel reinforcements. The tapes that are sewn on the ribs.

3.2.106 Rib pocket. A pocket made by sewing lengths of tape to the pilot chute to contain the ends of the frame.

3.2.107 Ripcord. The device consisting of a ripcord grip, cable, and locking pins used to secure the folded parachute in the pack and to release the canopy for deployment.

3.2.108 Riser. A webbing connecting the harness or the suspended load and the suspension lines of a canopy.

3.2.109 Saddle. The part of the main lift web of the harness that provides a seat or sling for the wearer.

3.2.110 Searing. A method of cutting or sealing ends of nylon cord, tape, or webbing by melting them to prevent raveling.

3.2.111 Section. One of the pieces of cloth making up the gore of a round type canopy.

3.2.112 Serving. A method of wrapping or binding the ends of lines or cords to prevent raveling.

3.2.113 Shoulder strap. The harness webbing that crosses the shoulders of the wearer.

3.2.114 Skirt. The reinforced hem forming the edge of the canopy.

3.2.115 Sleeve, deployment. A type of deployment device using fabric and webbing enclosing the entire full length of the canopy.

3.2.116 Slider. A reefing device that controls the opening of a canopy by sliding down the suspension lines during canopy inflation.

3.2.117 Slider reinforcements. The webbing and tapes that are sewn on the slider.

3.2.118 Spanwise. The direction of the leading and trailing edges, perpendicular to the direction of flight on gliding type parachutes.

3.2.119 Spanwise seams. The seams that join the spanwise panels of the upper and lower glide surfaces of gliding type parachutes..

3.2.120 Spring assembly, ejector. A device that assists the deployment of the pilot chute.

3.2.121 Trailing edge. The rear edge of the canopy to which the control lines are attached on a gliding type parachute May also refer to the edge down-stream of the airflow on a ribbon or section of cloth for ribbon and ring slot parachutes.

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.

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

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.

3.4.8 Folder. A device used as an attachment to a sewing machine to guide and fold fabric.

3.4.9 Gage. The measured distance between needles on a sewing machine. Also referred to as the capacity of a folder.

3.4.10 Hand tack. A stitch produced by hand sewing.

3.4.11 Loose stitches. Thread that does not lie smoothly on the surface of the fabric.

3.4.12 Margin. The space from the outer row of stitching to edge of the fabric or fold of the fabric.

3.4.13 Missing stitches. Space between stitches in the same row in which there is no thread.

3.4.14 Needle damage. The partial or complete yarn severance or fiber fusing caused by the needle passing through a fabric during sewing.

3.4.15 Overedge. The stitching around the outer edges of fabric that prevents the edges from raveling or fraying.

3.4.16 Overfold. An excess of material causing the edge of an inner fold to double, wrinkle, or pleat.

3.4.17 Overlap. The distance one material, thread, or cord extends over another material, thread, or cord.

3.4.18 Pleat. A fold sewn in fabric.

3.4.19 Runoff. Stitching not on seam or fabric.

3.4.20 Skipped stitches. Threads that are not interlocked.

3.4.21 Stitch splicing. Used when a bobbin has run out or similar during sewing;

characterized by stitch overlap on one end

3.4.22 Stitch repair. A section of stitching is removed and replaced due to defective stitching; characterized by stitch over lap on each end

3.4.23 Stitches per inch. The number of needle penetrations per linear inch where the threads are interlocked.

3.4.24 Stitching. Sewing, normally by machine, to join two or more pieces of fabric by thread.

3.4.25 Tight stitches. Thread under excess tension causing one sewing thread to lie on surface of fabric or causing puckering of fabric.

3.4.26 Uneven stitching. Inconsistent stitch length within a measured distance.

3.4.27 Tucks. A shortening of material caused by pulling fabric up in folds and stitching across the gathered fabric.

3.4.28 Underfold. Insufficient material folded inside a seam.

4. GENERAL REQUIREMENTS

4.1 Limitation of use. The conditions described in the defect listing herein will not be used for manufacturing purposes to extend specified tolerances of drawing requirements. Items should meet drawing requirements, therefore, immediate action will be taken to correct the causes of all defects. This document is not intended to cover all defects that may be encountered during the manufacture of parachutes and components. When deviations from the drawings or specifications are encountered that are not covered by this standard, final disposition by the procuring activity shall be required.

4.2 Interpretation of classification of defect tables. Conditions listed in tables III through XIX apply only in the direction of tolerance specified in the applicable drawings, specification, or standard. When the tolerance is called out in one direction, for example, minus 1, the variation shall apply only in the minus direction. When the tolerance is called out plus or minus, the variation may be taken in either direction. Notes are included as necessary under description of defects to ensure clarity and preclude the misinterpretation of requirements.

5. DETAILED REQUIREMENTS

5.1 Inspections and tests.

5.1.1 Component and material inspection. Components and materials shall be inspected as specified in the applicable end item specification.

5.1.2 In-process inspection of the product.

5.1.2.1 Material cutting. Controls shall be established to assure the accuracy and serviceability of patterns and the accuracy of webbing and cord cutting tables.

5.1.2.2 Manufacturing. Inspection will be performed at the inspection stations established by the contractor to control the quality of the parachute systems and components during manufacture. Any defects found during in-process inspection are to be repaired in accordance with applicable manufacturing specification.

5.1.3 Final inspection of the product.

5.1.3.1 Examination of items. Each parachute assembly or component thereof will be inspected for all manufacturing operations and material requirements that have not been previously inspected and accepted through in-process inspection. The misassembly of any components or individual parachute system will be cause for rejection. The acceptance number for major/critical defects shall be zero and the number of minor defects shall not exceed the quantities set forth in table I, II or III.

5.1.3.2 Examination of cloth, tape, and webbing. The cloth, tape, and webbing shall be examined visually to detect holes, snags, strains, stains, or other defects. Unless otherwise specified herein, encountered defects shall be classified in accordance with the classification of defect tables in the applicable material specification. Any material defects in the finished canopy (regardless of cause) that are minor will be acceptable, and any major/critical defect will be cause for the canopy to be rejected.

5.1.3.3 Examination of seams, hems, and stitching. The seams of canopies and pilot chutes will be examined for conformance with drawing details by projection of a 40-watt (minimum) fluorescent light through the canopy. Canopies made from tape and webbing shall be examined visually. Seams and hems shall be examined for the proper number of stitches per inch, broken or missing stitches, and proper construction. Defects discovered during these examinations will be classified in accordance with the classification of defect tables herein.

6. NOTES

(This section contains information of a general or explanatory nature that may be helpful, but is not mandatory.)

6.1 Intended use. This document is intended for defining the major/critical and minor classifications necessary to determine the acceptability of various parachutes for Government procurement purposes.

6.2 Past usage. Definitions of defects were previously provided in MIL-STD-105, "Sampling Procedures and Tables for Inspection by Attributes". General quality assurance terms were specified in MIL-STD-109, "Quality Assurance Terms and Definitions". These standards are no longer referred to in this document.

6.3 Subject term (key word) listing.

canopy harness MC6 seams cargo hems MRPS skirt cascade LCADS pack stitching chute LCLA personnel T11R deployment main reserve tape gliding MC-4 ripcord webbing

6.4 Changes from previous issue. The margins of this specification are marked with vertical lines to indicate where changes from the previous issue were made. This was done as a convenience only, and the Government assumes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the requirements of this document based on the entire content irrespective of the marginal notations and relationship to the last previous issue.

TABLE I. Personnel parachutes – guideline for maximum allowable errors per canopy.

Classification No. Item Major/Critical Minor

1. Canopies (solid cloth, round, extended skirt) Troop and rescue 0 8 Emergency 24 feet 0 5 Emergency 26 feet 0 6 Emergency 28 feet 0 6 Canopies (square, gliding type, main and reserve) 0 8

2. Pilot chute and drogue 0 3

3. Deployment bag and diaper 0 3

4. Pack/container Troop and rescue (excluding static line) 0 4 Emergency (except chest style) 0 5 Chest style (including reserve) 0 3 Container (integrated main and reserve) without harness – MC-4 only 0 5

5. Harness 0 5

6. Riser 0 1

7. Static line 0 2

8. Integrated pack and harness 0 8 Container (integrated main and reserve) with harness – MC-4 only 0 9

9. Bridle lines, straps, lanyards and pockets 0 2

10. Spring assembly, ejector 0 3

TABLE II. Cargo, deceleration, extraction, recovery, special weapon, and low cost parachute systems and containers – guideline for maximum allowable errors per canopy.

No. Item Major/Critical Minor

A. Cargo

1. Canopies (solid cloth, round, extended skirt) Up to 25 feet in diameter 0 10 Over 25 feet in diameter 0 20 Over 50 feet in diameter 0 30 Over 75 feet in diameter 0 40

2. Canopies (ribbon and ring slot) Up to 25 feet in diameter 0 10 Over 25 feet in diameter 0 20

3. Canopies (guide surface) 0 5

4. Pilot chute 0 3

5. Deployment bags and packs 0 10

6. Risers, static lines, bridles, straps, retainers, and adapter webs 0 5

B. Low Cost and/or Low Cost Low Altitude aerial delivery systems (LCADS, LCLA)

1. Canopies:

High velocity (HV) Spider parachute (without slider) 0 25 Low velocity (LV) BAT parachute 0 40 Stalker, cross parachute 0 25 Low cost container (LCC) 0 10

2. Deployment bag assemblies 0 10

3. Bridle assembly, Slider, Line spreader, Static line, Strap assembly (all 4 straps) 0 5

NOTE: In all of the following tables, all references in the form of "up to" are inclusive.

TABLE III. Classification of defects – solid and extended skirt parachute canopies – personnel.

No. Defect Major/Critical Minor

1. Improper assembly of vent reinforcement band 101

2. Vent reinforcement band overlap Up to 1/4 inch minus 201 Over l/4 inch minus 102 Over 1 inch plus 202

3. Vent hem outside stitching margin from edge of webbing 1/16 to 3/16 inch 203 Over 3/16 inch 103 All rows of stitching not through reinforcement webbing 104

4. Vent loop length (finished dimension) Up to 1/2 inch plus 204 Over 1/2 inch plus 105 Minus direction any length 106

5. Vent line length (finished dimension) Up to 1/4 inch 205 Over 1/4 inch 107

6. Variation in vent line length per set

Up to 1 percent 206 Over 1 percent 108

7. Twisted vent line (flat) 109

8. Twisted vent line (core or coreless braid) Over 360 degrees 207 Over 360 degrees, causing kinks in line when relaxed 110

9. Gore width at vent, centerline to centerline on main seam or as stated in TDP Up to 1/4 inch 208 Over 1/4 inch 111

10. Gore width at skirt, centerline to centerline on main seam or as stated in TDP Up to 1/2 inch 209 Over 1/2 inch 112

TABLE III. Classification of defects – solid and extended skirt parachute canopies – personnel – Continued.

No. Defect Major/Critical Minor

11. Cross and main seams, improper type or improper assembly 113

12. Open seams 114

NOTE: Seams will be classified as open when one or more stitches joining a seam are broken or when two or more skipped stitches occur. Conditions repaired by either re-stitching or overstitching as specified will not be scored as a defect.

13. Overfold in main seam Up to 1/2 inch or extended into center channel 210 Over 1/2 inch 115

14. Underfold in main seam

A 4-needle seam not caught by 3 rows of stitches by at least 1/16 of an inch 116 3 intermittent underfolds of a 2-needle seam up to 2 inches long and less than 12 inches apart 211 More than 3 intermittent underfolds, up to 2 inches long and less than 12 inches apart 117

Underfold more than 4 inches in length 118

15. Overfold and underfold in cross seam

Underfold 1/8 to 3/16 inch and up to 8 inches long 212 Underfold over 8 inches long 119 Up to 3 intermittent underfolds, 3/16 inch and up to 2 inches long, over 12 inches apart 213 More than 3 intermittent underfolds, 3/16 inch and up to 2 inches long, and less than 12 inches apart 120 Overfold 1/8 to 1/4 inch, full length of seam 214 Overfold over 1/4 inch any length 121

16. Fullness in seam width Main seam 1/8 to 1/2 inch 215 Over 1/2 inch 122 Cross seam 1/8 to 1/4 inch 216 Over 1/4 inch 123

No. Defect Major/Critical Minor

17. Fullness not evenly distributed along radial tape (SF10A) 217

18. Wrinkles and pleats in cross and main seams

Cross seams 1/16 to 1/8 inch and 1 per seam 218 1/16 inch and more than 1 per seam 124 1/16 inch and more than 6 per canopy 125 Over 1/8 inch 126

Main seams (canopies up to 35 feet in diameter) 1/16 to 1/8 inch and 1 per seam 219 1/16 to 1/8 inch and more than 1 per seam 127 1/16 to 1/8 inch and more than 6 per canopy 128 Over 1/8 inch 129

Main seams (canopies over 35 feet and up to 65 feet in diameter) 1/16 to 1/8 inch and 2 per seam 220 1/16 to 1/8 inch and more than 2 per seam 130 1/16 to 1/8 inch and more than 9 per canopy 131 Over 1/8 inch 132

Main seams (canopies over 65 feet in diameter) 1/16 to 1/8 inch and 3 per seam 221 1/16 to 1/8 inch and more than 3 per seam 133 1/16 to 1/8 inch and more than 12 per canopy 134 Over 1/8 inch 135

19. Vent and skirt hems improperly formed

Raw edge showing 136 Intermittent underfold where edge is caught with 2 rows of stitching 222 Underfold where edge is caught with 1 row of stitching 137

20. Vent hem fold over main seam around webbing not straight 223

21. Matching of centerlines of seams when folded

1/8 to 1/4 inch 224 Over 1/4 inch 138

22. Wrinkles, pleats, or folds in skirt and vent hems that do not extend into thegore fabric

No. Defect Major/Critical Minor

1/4 to 1/2 inch and 1 per gore 225 Over 1/2 inch and more than 1 per gore 139 Over 1/2 inch and more than 12 per canopy up to 35 feet 140 Over 1/2 inch and more than 14 per canopy over 35 feet and up to 65 feet 141 Over 1/2 inch and more than 18 per canopy over 65 feet 142

23. Wrinkles, pleats, or folds in skirt and vent hems extending into the gore fabric

1/16 to 1/8 inch and 1 per gore 226 Over 1/16 inch and more than 1 per gore 143 Over 1/16 inch and more than 6 per canopy up to 35 feet in diameter 144 Over 1/16 inch and more than 12 per canopy over 35 feet and up to 65 feet in diameter 145 Over 1/16 inch and more than 18 per canopy over 65 feet in diameter 146 Over 1/8 inch 147

24. Skirt hem outside stitching margin from edge of webbing 1/16 to 3/16 inch 227 Over 3/16 inch 148 Any row of stitching not through skirt band webbing 149

25. Fold over of main seam around skirt webbing not straight 228

26. Matching of centerline of seams when folded

1/8 inch to 1/4 inch 229 Over 1/4 inch 150

27. Skirt hem formed by more than 2 pieces of tape or webbing unless otherwise specified on the applicable drawing 151

28. Tape or webbing used to form skirt hem does not extend across a minimum of 4 gores 152

29. Tucks, where section of gore fabric caught in stitching of seams or hems Up to 1/4 inch wide and up to 1/2 inch long 230

No. Defect Major/Critical Minor

Over 1/4 inch wide regardless of length 153 Over 1/2 inch wide regardless of width 154

30. Mismatching of cross seams

First seam from vent over 2 inches and up to 2-1/2 inches 231 First seam from vent over 2-1/2 inches 155 All other seams over 2-1/2 inches and up to 3 inches 232 All other seams over 3 inches 156 All seams on SF10A greater than ½ inch 157

31. Vent lines out of sequence 158

32. Suspension and vent line overlap on canopy

Up to 1/8 inch minus 233 Over 1/8 inch minus 159 Over 1/4 inch plus 234

33. Suspension lines not in proper channel or lines crossed 160

34. Cut, frayed, or damaged suspension, control or vent lines 161

35. Variation in suspension line length per set, between vent and skirt

Up to 1/2 percent 235 Over 1/2 percent 162

36. Variation in suspension line length between vent and skirt

Up to 1 percent 236 Over 1 percent 163

37. Twisted suspension line, between vent and skirt (flat)

In channel, up to 360 degrees 237 In channel, over 360 degrees 164

38. Twisted suspension line between vent and skirt (core or coreless braid) Over 180 degrees to 360 degrees 238 Over 360 degrees 165

No. Defect Major/Critical Minor

39. Twist between line reinforcement at skirt and 3-inch zigzag stitching above the skirt, when suspension lines are continuous through canopy (measured by pulling line under 5 pounds of tension between vent and line reinforcement and observing the rotation of zigzag stitching)

90 to 180 degrees 239 Over 180 degrees 166 Line not placed between 2 ply’s of material 167

40. Variation in suspension line length between skirt and attaching point

Up to 1 percent 240 Over 1 percent 168

41. Variation in suspension line length per set between skirt and attaching point

Up to 1/2 percent 241 Over 1/2 percent 169

42. Twisted suspension line between skirt and attaching point (flat), except hem rigged canopy 170

43. Twisted suspension line (flat), hem rigged canopy

180 to 360 degrees 242 Over 360 degrees 171

44. Twisted suspension line between skirt and attaching point (core and coreless braid) Over 360 degrees 243 Over 360 degrees causing kinks in the line 172

45. Twisted suspension line between suspension line loop and attaching point (SF10A) Over 180 degrees 173

46. Suspension line length, main seams, extended gore trailing edge length and break slots out of symmetry (SF10A) 174

47. Stitching on canopy

1 stitch per inch over or under the number specified, up to 2 inches long and one place per seam (size 3 through 6 thread) 244

No. Defect Major/Critical Minor

1 stitch per inch over or under the number specified, over 2 inches long (size 3 through 6 thread) 175

More than 1 stitch per inch over or under the number specified (size 3 through 6 thread) 176 2 stitches per inch over or under the number specified, up to 2 inches long and one place per seam (size B through FF thread) 245 2 stitches per inch over or under the number specified, over 2 inches long (size B through FF thread) 177 More than 2 stitches per inch over or under the number specified (size B through FF thread) 178

NOTE: For B or E size thread only, up to 14 stitches per inch, type 301 or 401 stitches in accordance with ASTM D 6193, will be allowed for a length not over 2 inches in any one place with a minimum distance between locations of 12 inches. Over 14 stitches, or 14 stitches more than 2 inches long or less than 12 inches apart, shall be classified a major defect.

NOTE: When a double thickness or more occurs in fabric being sewn or where pressure must be applied by an operator to sew over reinforcement tapes and webbings, the number of stitches per inch defects will be classified as follows: within the major defect category, minor defect; and within the minor defect category, no defect.

NOTE: When the end item specification forbids repair to defective stitching, it shall be classified as a major defect.

Broken or missing stitches Up to 1/4 inch 179 Over 1/4 inch 180

2 or more consecutive skipped stitches 181 Missing or incomplete stitch pattern (for example, bartack or zigzag) 182 Backstitch missing 183 Backstitch short

Less than 1/4 inch 246 More than 1/4 inch 184

Runoff, 2 or more stitches into single cloth or beyond seam or hem margins 185

Up to 1/4 inch 247

No. Defect Major/Critical Minor

Over 1/4 inch 186 Zigzag stitches where less than 85 percent of the stitches penetrate through suspension lines 187 Tension too loose or too tight, up to 3 inches per seam 248 Tension too loose or too tight, over 3 inches per seam 188 Kinks, intermittent, less than 2 inches apart 249 Stitch pattern lengths not as specified (stitch patterns up to 5 inches long)

Up to 1/8 inch longer or shorter 250 Over 1/8 inch shorter 189 Over 1/8 inch longer 251

Stitch pattern lengths not as specified (stitch patterns over 5 inches long)

Up to 1/4 inch longer or shorter 252 Over 1/4 inch shorter 190 Over 1/4 inch longer 253

48. Frequency of repair to stitching and splicing on canopy shall be classified according to the following table.

More than the number of splices and repairs in the table 191 Up to and including the number of splices and repairs in the table 254

Length of seams (inches) Splices Repairs 0 – 2 0 0 3 – 12 0 1 13 – 72 0 2 73 – 240 1 3 241 – 360 2 4 361 – 480 3 5 481 – 600 4 6 Skirt band 1 per 600 inches 1 per 100 inches

49. Length of splices and repairs to stitches

Overlap less than 2 inches 192 Overlap from 4 inches to 7 inches 255 Overlap more than 7 inches 193

50. Needle damage (cuts or chews) Up to 1/8 inch long and 1 per canopy up to 35 feet in diameter 256

No. Defect Major/Critical Minor

Over 1/8 inch long or more than 1 per canopy up to 35 feet in diameter 194

Up to 1/8 inch long and 2 per canopy 35 feet in diameter and over 257 Over 1/8 inch long or more than 2 per canopy 35 feet in diameter and over 195

51. Holes, darns and repairs

Holes over 1/8 inch in diameter or over 1/4 inch long 196 Darns, more than 1 per section 197 Darns, more than 3 per canopy up to 50 feet in diameter 198 Darns, more than 10 per canopy from 50 feet in diameter to 75 feet in diameter 199 Darns, more than over 15 per canopy 75 feet in diameter and over 101a

52. Ends of webbing, tape, and cord not seared, scissor cut, waxed or serged as specified 258

53. Improper routing of control line grouping 102a

54. Pocket band free length

Up to 1/8 inch 259 Over 1/8 inch 103a

55. Pocket depth, centerline main seam to stitch pattern on skirt band

Up to 1/8 inch 260 Over 1/8 inch 104a

56. Suspension line attaching loop, up to 2 inches in length

Note: On SF10A this refers to loop at bottom of line attachment loop Up to 1/8 inch 261 Over 1/8 inch 105a

57. Suspension line attaching loop, over 2 inches and up to 4 inches in length

Up to 1/4 inch 262 Over 1/4 inch 106a

58. Location of reefing line cutter bracket from edge of skirt

Up to 1/8 inch 263

No. Defect Major/Critical Minor

Over 1/8 inch 107a

59. Location of reefing line arming cord from edge of skirt

Up to 1/8 inch 264 Over 1/8 inch 108a

60. Improper assembly, construction detail or viewer note per TDP 109a

61. Component missing per TDP 110a

62. Identification marking illegible, incorrect or missing 111a

63. Incorrect or defective material 112a

64. Dark identification threads not removed or markings not yellow (for special weapon parachutes, other than those identified as training units) 266

65. Material unclean 113a

66. Searing over stitching 114a

67. Thread ends not clipped Up to 2 inches 267 Over 2 inches 115a Over ½ inch at anti-inversion net 116a

No. Defect Major/Critical Minor

TABLE IV. Classification of defects – ring slot and ribbon parachute canopies.

No. Defect Major/Critical Minor

1. Improper assembly of vent reinforcement band 101

2. Vent reinforcement band overlap Up to 1/4 inch minus 201

Over 1/4 inch minus 102 Over 1/2 inch plus 202

3. Vent loop length (finished dimension)

Up to 1/2 inch 203 Over 1/2 inch 103

4. Vent line length (finished dimension)

Up to 1/4 inch 204 Over 1/4 inch 104

5. Variation in vent line length per set

Up to 1 percent 205 Over 1 percent 105

6. Twisted vent line (flat) 106

7. Twisted vent line core or coreless braid

Over 360 degrees 206 Over 360 degrees causing kinks in line when relaxed 107