Attachment 0002 - MIL STD 849D.pdf

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INCH-POUND

MIL-STD-849D

17 December 2019

SUPERSEDING

MIL-STD-849C

31 July 2009

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:

DLA Aviation -VEB, 8000 Jefferson Davis Highway, Richmond, VA 23297-5616, or e-mailed to STDZNMGT@dla.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST database at https://assist.dla.mil/.

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MIL-STD-849D

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CONTENTS

PARAGRAPH PAGE

1. SCOPE

1.1 Scope

1.2 Purpose

1.3 Application

2. APPLICABLE DOCUMENTS

2.1 General

2.2 Government documents

2.3 Non-Government publications

2.4 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 Subject term (key word) listing

6.3 Changes from previous issue

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TABLE

I Personnel parachute systems – guideline for maximum allowable errors per item

II Cargo, deceleration, extraction, recovery, and special weapon systems – guidelines for maximum allowable errors per item

III Classification of defects – canopies: solid and extended skirt parachutes

– personnel

IV Classification of defects – canopies: ring slot and ribbon parachutes

V Classification of defects – pilot chutes, drogues, and ejector spring assembly

VI Classification of defects – packs or containers, and deployment bags – personnel

VII Classification of defects – harnesses, risers, static lines, bridle lines, straps, lanyards, pockets, and cloth ripcord handles – personnel

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 – integrated pack and harness – personnel

XI Classification of defects – canopies: square, gliding type, main and reserve – personnel

XII Classification of defects – pilot chutes, drogues, and ejector spring assembly - MC-4 and RA-1 only

XIII Classification of defects – integrated pack and container (without harness), deployment bag and pocket – MC-4 and RA-1 only

XIV Classification of defects – harness, riser, bridle line, strap, and lanyard –

MC-4 and RA-1 only

XV Classification of defects – canopies: solid and extended skirt parachute – cargo

XVI Classification of defects – canopies: cross-cruciform parachute with slider – personnel

XVII Classification of defects – deployment sleeve – personnel

XVIII Classification of defects – canopies: square, gliding type – cargo

XIX Classification of defects – harness: joint precision airdrop system – cargo

XX Classification of defects – soft link – cargo…………………………………. 89

XXI Classification of defects – parachute system: one time use – cargo….………90

CONCLUDING MATERIAL..…………………………………………………………………95

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 Government documents.

2.2.1 Specifications and standards. The following specifications and standards form a part of this document to the extent herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract.

DEPARTMENT OF DEFENSE STANDARDS

MIL-DTL-9401 Canopy, Parachute, Ring Slot, General

Specification for Construction of

(Copies are available online at https://quicksearch.dla.mil)

2.3 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 D6193 Standard Practice for Stitches and Seams

(Copies of this document are available online at https://www.astm.org/)

2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this standard takes precedence. Nothing in this document, 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 may result in failure or 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 form, fit 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 Arm attaching seam. Seams created on cross-cruciform parachute when canopy arms are sewn to canopy center section.

3.2.5 Arm section. Areas of a canopy below the arm attaching seams.

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

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

It may or may not be adjustable.

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

3.2.9 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.

3.2.10 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.

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

3.2.12 Band, spring, parachute pack opening. 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.

3.2.13 Bandstow. A webbing or tape loop sewn to a packtray, deployment bag, or sleeve, for attachment of rubber retainer bands.

3.2.14 Band, retainer. An elastomeric band used to hold folded suspension lines or static lines to deployment bags or parachute packs.

3.2.15 Bias. A cut or seam running obliquely across the yarns of a fabric.

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

3.2.17 Block stamp wording. Headings for the stamp or markings used to identify a part such as “Contract No:”, “Cage Code.”, etc., which precede the actual identifying information.

3.2.18 Bottom, false. A piece of fabric sewn to the inside of a pack to retain the frame; it also serves as a base for stitching the suspension line retaining loops.

3.2.19 Break cord. A thread or tape, tied between parachute components that is intended to break under desired load during deployment.

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

3.2.21 Burns, friction. Deterioration of individual yarns caused from heat generated by the rubbing together of a textile and another surface.

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

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

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

3.2.23.2 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.

3.2.23.3 Canopy, guide surface. A canopy made from cloth similar to flat circular canopy except the guide surface panels are attached to the edge of roof panels to enhance stability.

3.2.23.4 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.

3.2.23.5 Canopy, ring sail. A canopy of ring slot 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).

3.2.23.6 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.

3.2.24 Cap seam. The top seam of the pilot chute, which joins the gores and the pilot chute cap (disk or crown) together.

3.2.25 Cascade. The junction of two or more suspension lines before attachment to the risers on gliding type parachutes.

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

3.2.27 Center section. Top area of a canopy above the arm attaching seams.

3.2.28 Channel canopy. The space or opening through which the suspension lines or radial tapes 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.

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

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

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

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

3.2.33 Chute. The term used interchangeably for the word "parachute”.

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

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

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

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

3.2.38 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.

3.2.39 Cord, arming. The cord that arms the reefing line cutter or other actuation device when pulled.

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

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

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

3.2.43 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.

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

3.2.45 Dart. A short tapered seam.

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

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

3.2.48 Drogue. Typically a small first-stage parachute canopy in a system used for initial deceleration and stabilization, or extraction.

3.2.49 Elastic, pack-opening. Elastomeric 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.

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

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

3.2.52 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.

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

3.2.54 Foreign object. Something found in the end item that does not belong there.

3.2.55 Fullness, canopy. Volume added to a gore by puckering and gathering seams of a certain length into small wrinkles or folds along radial tape of a shorter length. Puckering and gathering is evenly spread out along the full length of the seam.

3.2.56 Fullness, seam. Excess cloth between rows of stitching in a seam which is greater than stitch row spacing.

3.2.57 Glide surfaces, upper and lower. The panels forming the top and bottom glide surfaces of a gliding type parachute.

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

3.2.59 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.

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

3.2.61 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.

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

3.2.63 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

3.2.64 Hesitator, skirt. A device that restricts the skirt of the canopy from opening, preventing inflation until completion of line stretch, at which time the hesitator line breaks and allows inflation of the canopy.

3.2.65 Holes, drill. Small pinholes used as optional manufacturing aid to indicate location on textile components. Nonpermanent drill holes can be formed using a cold drill.

Permanent drill holes resembling a small burn mark can be formed using a hot drill or laser.

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

3.2.67 Housing, ripcord. A flexible tube through which the ripcord cable is passed.

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

3.2.69 Keeper. A band formed from webbing or elastic. Used to bind excess webbing, secure components to a harness or load, or provide a confluence point for suspension lines and risers.

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

3.2.71 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.

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

3.2.73 Knot, surgeon's. A type of knot typically used to terminate double strand hand tacking, that is similar to a square knot with two turns instead of one for the first knot layer. This type of knot is commonly used in conjunction with a square knot.

3.2.74 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.

3.2.75 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.

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

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

3.2.78 Lift web. The main harness webbing which runs vertically along the front torso or payload.

3.2.79 Line continuity. Free and clear routing to certain areas on canopy to ensure proper steering of canopy.

3.2.80 Line, control. Used to steer and maneuver canopy, also known as steering or brake lines.

3.2.81 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.

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

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

3.2.84 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.

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

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

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

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

3.2.89 Line group, suspension. All suspension lines on one connector link.

3.2.90 Line set, suspension. All suspension lines on one parachute assembly.

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

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

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

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

3.2.95 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.

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

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

3.2.98 Main seam. The seam sewn from skirt to vent/apex holding gores together and used as a guide for the suspension line or radial tape on a round type parachute.

3.2.99 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. This definition applies when MIL-DTL-9401 is referenced.

3.2.100 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.

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

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

3.2.103 Panel. Individual section of fabric sewn to another fabric section, using cross seams to form a gore. Also refers to the continuous length of cloth cut from a pattern.

3.2.104 Panel section. Area of a panel that is subdivided by seams and/or reinforcement tape.

3.2.105 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.

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

3.2.105.2 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.

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

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

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

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

3.2.105.7 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.

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

3.2.105.9 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.

3.2.105.10 Parachute, reserve. A secondary parachute, worn while making a premeditated parachute jump, to be used in the event that the main parachute fails.

3.2.105.11 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.

3.2.105.12 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.

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

3.2.106 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.

3.2.107 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.

3.2.108 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.

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

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

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

3.2.112 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.

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

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

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

3.2.116 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.

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

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

3.2.119 Ripcord. A device that secures the folded parachute in the pack and provides a release for the canopy in deployment.

3.2.120 Riser. The portion of a suspension system between the lower end of a group of canopy suspension lines, and the point of attachment to the load.

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

3.2.122 Searing. A method of cutting or sealing ends of heat sensitive material, such as nylon, using a hot tool to prevent raveling.

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

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

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

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

3.2.127 Sleeve, deployment. A deployment aid using fabric and webbing which may enclose the full length of the canopy.

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

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

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

3.2.131 Spanwise seams. The seams joining the spanwise panels of the upper and lower gliding surfaces of some gliding type parachutes.

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

3.2.133 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.

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

3.2.135 Upper cascade. Any junction of control lines above the lower cascade.

3.2.136 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 Brazing. A joining process using a high temperature filler metal to bond adjoining metals.

3.3.3 Composite. Material made from two or more components with different properties that when combined, produce a material with characteristics different from the individual components.

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

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

3.3.6 Grommet. A metal eyelet that interlocks with a washer, used as reinforcement around a hole in fabric.

3.3.6.1 Grommet, plain. A metal eyelet that interlocks with a plain washer.

3.3.6.2 Grommet, rolled rim. Interlocks with spur washers to provide a firm, tight setting.

3.3.7 Hardness. Resistance of metal to plastic deformation usually from indentation or penetration by means such as abrasion, drilling, impact, scratching and/or wear. Results can be used to determine tensile strength in some materials, typically metal.

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

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

3.3.10 Soldering. A joining process using a low temperature filler metal to bond adjoining metals.

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

3.3.12 Washer. A thin plate with a hole that works with a grommet to make a secure

3.3.12.1 Washer, plain. Basic reinforcement which provides support for the grommet

3.3.12.2 Washer, spur. A washer that has interlocking teeth which provide a firm, tight grasp for the grommet setting.

3.3.13 Welding. A joining process that melts similar adjoining metals to form a bond.

3.4 Specific definitions of parachute sewing terms and conditions.

3.4.1 Backstitch or backtack. The start and/or finish of a row of stitching by sewing back over the original stitching a short distance to retard raveling.

3.4.2 Bartack. A concentrated row of stitching used to reinforce points of stress. Often resembles a zigzag pattern.

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

3.4.4 Bird nest (stitching nest). Tangled mass of thread resembling a bird’s nest, which can occur on the needle or bobbin side.

3.4.5 Broken stitch. A break in sewing thread.

3.4.6 Bunched stitching. Non-uniform distribution of stitches resulting in excessive stitching in a single area.

3.4.7 Cross box / box-x. A sewing pattern that consists of a stitched box with an X sewn from corner to corner.

3.4.8 Crowd stitching. The intentional concentration of a stitch pattern to secure the end of a stitch pattern, usually at the end of a row of stitching to reinforce the stitch.

3.4.9 Double W / 4-point. A sewing pattern that consists of two parallel rows with two or more equally spaced crossing rows in between them forming a double W (or 3-point), or a 4-point.

Also referred to as a cross stitch.

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

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

3.4.12 Hand tack. A stitch produced by hand sewing.

3.4.13 Kink. A short length of thread that protrudes from the surface of a stitch line that doubles back on itself to form a twisted or knotted loop. Also referred to as knotty thread.

3.4.14 Loop. A continuous thread that protrudes from the surface of a stitch line, forming a raised loop instead of a flat stitch.

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

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

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

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

3.4.19 Open seam. One or more consecutive broken stitches or two or more consecutive skipped stitches in a seam.

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

3.4.21 Overfold. An excess of material causing the edge of an inner fold to double.

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

3.4.23 Pleat. A fold sewn in fabric. Pleats may be inserted by design or may be the result of unintentional gathering of cloth.

3.4.24 Ravel. To come undone, separate, untwist, unwind, or unweave, leaving a frayed or ragged edge.

3.4.25 Replacement stitching. Removal of defective stitching followed by resewing the seam or stitch pattern.

3.4.26 Runoff. Stitching that run off the intended seam, fabric, tape, webbing, or cord.

3.4.27 Skipped stitches. Long float in a stitch line due to stitches that fail to interlace or interloop.

3.4.28 Stitch per inch. Frequently referred to as SPI. In straight stitching, the number of needle penetrations per linear inch when the threads are interlocked. Zig-zag stitching may be defined either by number of points along one side or by total stich count.

3.4.29 Stitch reinforcement. Stitch repair which lies adjacent to or superimposes defective stitching. Defective stitching is not removed.

3.4.30 Stitch repair. A section of stitching that is removed and replaced, or reinforced, due to defective stitching, characterized by stitch overlap on each end.

3.4.31 Stitch splicing. Restarting a stitch row that has ceased because, for example, a bobbin ran out of thread. Stitch splice is characterized by stitch overlap on one end.

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

3.4.33 Tight stitches. Thread under excess tension causing the interlocking knots to lie on either surface of fabric, or causing puckering of fabric.

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

3.4.35 Tucks. A shortening of material caused by pulling fabric up in folds and stitching across the gathered fabric, generally parallel to the seam.

3.4.36 Underfold. Insufficient material folded inside a seam.

3.4.37 Zigzag stitch. A stitch formation of alternating left and right throw stitches.

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 are required to 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 XXI apply only in the direction of tolerance specified in the applicable drawings, specification, or standard. These conditions are defects that fall outside of the applicable drawing, specification, or standard requirements. When the tolerance is called out in one direction, for example, minus, 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 Inspection 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 incorrect assembly or construction 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 or II.

5.1.3.2 Inspection 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 defect in the finished canopy or component (regardless of cause) that are minor will be acceptable, and any major or critical defect will be cause for the canopy or component to be rejected.

5.1.3.3 Inspection 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 Subject term (key word) listing.

Canopy

Cargo

Cascade

Chute

Deployment

Harness

Hems

JPADS

Main

MC-4

MC-6

MIPRS

Pack

Personnel

RA-1

Reserve

Seams

SF10-A

Skirt

Sleeve

Stitching

T-11

T-11R

Tape

Webbing

6.3 Changes from previous issue. The margins of this standard 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 parachute systems - guideline for maximum allowable errors per item.

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

2 Canopies (square, gliding type, main and reserve) 0 8

3 Canopies (cross-cruciform) 0 8

4 Pilot chute and drogue 0 3

5 Deployment bag, diaper, and sleeve 0 3

6 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, 0 5

MC-4 and RA-1

Container (integrated main and reserve) with harness, MC-4 0 9

7 Integrated pack and harness 0 8

8 Harness 0 5

9 Risers 0 1

10 Static lines, bridle lines, straps, lanyards, pockets, and cloth ripcord handles 0 2

11 Spring assembly, ejector 0 3

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

Classification

TABLE II. Cargo, deceleration, extraction, recovery, and special weapon systems - guideline for maximum allowable errors per item.

No. Item Major/Critical Minor

1 Canopies (solid cloth, round, extended skirt)

Up to 25 feet in diameter 0 10

Greater than 25 feet in diameter 0 20

Greater than 50 feet in diameter 0 30

Greater than 75 feet in diameter 0 40

2 Canopies (ribbon and ring slot)

Up to 25 feet in diameter 0 10

Greater than 25 feet in diameter 0 20

3 Canopies (glide surface) 0 5

4 Canopies (square, gliding type)

Up to 500 sq. ft. 0 10

Greater than 500 sq. ft. and up to 2000 sq. ft. (JPADS 2K, 2K1T, 4K) 0 30

Greater than 2000 sq. ft. (JPADS 10K) 0 50

5 Pilot chute and drogue 0 3

6 Deployment bags and packs 0 10

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

8 Soft link 0 1

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

Classification

Table III. Classification of defects - canopies: solid and extended skirt parachutes - personnel.

No. Classification of defects Major/Critical Minor

1. Any dimension out of tolerance per TDP unless otherwise specified in this table 101

2. Improper assembly (construction detail, note, etc.) per TDP 102

3. Component missing per TDP 103

4. Material not as specified per TDP 104

5. Material with major or critical defects, as specified in the material specifications 105

6. Any foreign object found 106

7. Vent reinforcement band overlap

1/4 inch or less, minus 201

Greater than 1/4 inch, minus 107

Greater than 1 inch, plus 202

8. Vent hem outside stitching margin from edge of webbing

1/16 inch up to 3/16 inch 203

Greater than 3/16 inch 108

All rows of stitching not through reinforcement webbing 109

9. Vent loop length (finished dimension)

1/2 inch or less, plus 204

Greater than 1/2 inch, plus 110

Minus direction any length 111

10. Vent line length (finished dimension)

1/4 inch or less 205

Greater than 1/4 inch 112

11. Variation in vent line length per set

1 percent or less 206

Greater than 1 percent 113

12. Twisted vent line (flat) 114

13. Twisted vent line (core or coreless braid)

Greater than 360 degrees 207

Greater than 360 degrees, causing kinks in line when relaxed 115

14. Gore width at vent, centerline to centerline on main seam or as defined in TDP

1/4 inch or less 208

Greater than 1/4 inch 116

Classification

Table III. Classification of defects - canopies: solid and extended skirt parachutes - personnel - Continued.

No. Classification of defects Major/Critical Minor

Classification

15. Gore width at skirt, centerline to centerline on main seam or as defined in TDP

1/2 inch or less 209

Greater than 1/2 inch 117

16. Underfold (raw edge exposed in main or cross seam) 118

17. Overfold in main seam

1/2 inch or less, or extended into center channel 210

Greater than 1/2 inch 119

18. Underfold in main seam

A 4-needle seam not caught by three rows of stitches by at least 1/16 inch 120

Three intermittent underfolds, up to half the seam width of a 2-needle seam, 211

2 inches long or less, spaced closer than 12 inches apart

More than three intermittent underfolds up to half the seam width, 2 inches 121 long or less, spaced closer than 12 inches apart

Underfold, up to half the seam width, greater than 4 inches in length 122

More than half the seam width, any length 123

19. Overfold and underfold in cross seam

Underfold, 1/8 inch to 3/16 inch from folded edge of seam, 8 inches long or 212 less

Underfold, greater than 8 inches long 124

Up to three intermittent underfolds, 3/16 inch from folded edge of seam, 2 213 inches long or less, spaced further than 12 inches apart

More than three intermittent underfolds, 3/16 inch from folded edge of seam, 125

2 inches long or less, spaced closer than 12 inches apart

Overfold, quarter to half of seam width, full length of seam 214

Overfold, greater than half of seam width, any length 126

20. Overfold and underfold in SF10-A and T-11R main seam and cross seam

Overfold

1/8 inch up to 1/4 inch, any length 215

Over 1/4 inch, any length 127

Underfold

1/8 inch up to 1/4 inch, any length 216

Over 1/4 inch, any length 128

1/8 inch up to 1/4 inch, greater than 4 inches in length per seam 129

More than three intermittent underfolds, 1/8 inch up to 1/4 inch per seam, 130

2 inches long or less, spaced closer than 12 inches apart

21. Fullness in seam width, as measured per the following diagram:

Table III. Classification of defects - canopies: solid and extended skirt parachutes - personnel - Continued.

No. Classification of defects Major/Critical Minor

Classification

Main seam

1/8 inch up to 1/2 inch 217

Greater than 1/2 inch 131

Cross seam

1/8 inch up to 1/4 inch 218

Greater than 1/4 inch 132

Main seam and cross seam, SF10-A and T-11R 133

Greater than 1/8 inch

22. Puckering and gathering sewn in to create canopy fullness not evenly spaced along 219 radial tape of SF10-A canopy, or not present along the full length of seam

23. Wrinkles and pleats in cross and main seams

Cross seams

1/16 inch up to 1/8 inch and one per seam 220

1/16 inch up to 1/8 inch and more than one per seam 134

1/16 inch up to 1/8 inch and more than six per canopy 135

Greater than 1/8 inch 136

Main seams

1/16 inch up to 1/8 inch and one per seam 221

1/16 inch up to 1/8 inch and more than one per seam 137

1/16 inch up to 1/8 inch and more than six per canopy 138

Greater than 1/8 inch 139

24. Vent and skirt hems improperly formed (four rows of stitching)

Raw edge showing 140

Intermittent underfold where edge is caught with two rows of stitching 222

Underfold where edge is caught with one row of stitching 141

25. Vent and skirt hems improperly formed (two rows of stitching)

Raw edge showing 142

Intermittent underfold, half of seam width or greater, where edge is caught 143 with one row of stitching

26. Matching of centerlines of seams when vent and skirt hems are folded

1/8 inch up to 1/4 inch 223

Greater than 1/4 inch 144

27. Wrinkles or pleats in skirt and vent hems that do not extend into the gore fabric

1/4 inch up to 1/2 inch 224

Greater than 1/2 inch and more than one per gore 145

Table III. Classification of defects - canopies: solid and extended skirt parachutes - personnel - Continued.

No. Classification of defects Major/Critical Minor

Classification

Greater than 1/2 inch and more than twelve per canopy up to 35 feet diameter 146

Greater than 1/2 inch and more than fourteen per canopy greater than 35 up 147 to 65 feet diameter

Greater than 1/2 inch and more than eighteen per canopy greater than 65 feet 148 diameter

28. Wrinkles or pleats in skirt and vent hems extending into the gore fabric

1/16 inch up to 1/8 inch long and one per gore 225

1/16 inch or greater, and more than one per gore 149

1/16 inch or greater, and more than six per canopy 150

Greater than 1/8 inch long 151

29. Skirt hem outside stitching margin from edge of webbing

1/16 inch up to 3/16 inch 226

Greater than 3/16 inch 152

Any row of stitching not through skirt band webbing 153

30. Skirt hem formed by more than two pieces of tape or webbing, unless otherwise 154 specified on the applicable drawing

31. Tape or webbing used to form skirt hem does not extend across a minimum of four 155 gores

32. Tucks

1/4 inch wide or less, and 1/2 inch long or less 227

Greater than 1/4 inch wide regardless of length 156

Greater than 1/2 inch long regardless of width 157

33. Mismatching of cross seams

First seam from vent, 2 inches or greater and 2-1/2 inches or less 228

First seam from vent, greater than 2-1/2 inches 158

All other seams, greater than 2-1/2 inches and 3 inches or less 229

All other seams, greater than 3 inches 159

All seams on SF10-A, greater than required by TDP 160

T-11R cross seam misalignments greater than required by TDP 161

34. Vent lines out of sequence 162

35. Suspension and vent line overlap on canopy

1/8 inch or less, minus 230

Greater than 1/8 inch, minus 163

Greater than 1/4 inch, plus 231

36. Suspension lines not in proper channel or lines crossed 164

Table III. Classification of defects - canopies: solid and extended skirt parachutes - personnel - Continued.

No. Classification of defects Major/Critical Minor

Classification

37. Cut, frayed, or damaged suspension, control or vent lines 165

38. Variation in suspension line length per line group, between vent and skirt

1/2 percent or less 232

Greater than 1/2 percent 166

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

1 percent or less 233

Greater than 1 percent 167

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

NOTE: Does not apply to SF10-A or T-11R.

1/2 percent or less 234

Greater than 1/2 percent 168

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

NOTE: Does not apply to SF10-A or T-11R.

1 percent or less 235

Greater than 1 percent 169

42. Suspension line length, main seams, extended gore trailing edge length or break slots 170 out of symmetry on SF10-A or T-11R canopy

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

In channel, 360 degrees or less 236

In channel, greater than 360 degrees 171

44. Twisted suspension line between vent and skirt (core or coreless braid)

Greater than 180 degrees up to 360 degrees 237

Greater than 360 degrees 172

45. 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)

Greater than 90 degrees up to 180 degrees 238

Greater than…