Attachment 15 - Detail Specification for MJU-76B Infrared Countermeasure Flare.pdf

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DTL 201825313B

Original Design Activity:

CAGE Code 98747 15 April 2025

DETAIL SPECIFICATION

FOR SUPERSEDING

MJU-76/B INFRARED COUNTERMEASURE FLARE DTL 201825313

24 October 2023

Revision B

Prepared for and by: AFCLMC/EBHCC

6033 ELM LANE, BLDG 1247

HAFB, UT 84056

SUBMITTED BY: DATE: April 15, 2025

APPROVED FOR USE AS

PRODUCT BASELINE BY: DATE: April 15, 2025

DISTRIBUTION STATEMENT D: Distribution authorized to Department of Defense and U.S. DoD contractors only, CTI and Export Controlled, 15

April 2025. Other requests for this document must be referred to AFLCMC.EBHCC.CMFLARES@US.AF.MIL.

WARNING - This document contains technical data whose export is restricted by the Arms Export Control Act (Section 2751 of Title 22, United

States Code) or the Export Control Reform Act of 2018 (Chapter 58 Sections 4801-4852 of Title 50,United States Code). Violations of these export laws are subject to severe criminal penalties. Disseminate in accordance with provisions of DoD Directive 5230.25 and DoD Instruction

2040.02.

AMSC# N/A FSC 1370

X Quincy Stevens

Program Engineer, AFLCMC/EBHCC

X Steve Decker

Chief Engineer, AFLCMC EBHE

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Table of Contents

1. SCOPE

1.1 Scope

1.2 Definitions

2. APPLICABLE DOCUMENTS

2.1 Government Documents

2.1.1 Standards

2.1.2 Drawings

3. REQUIREMENTS

3.1 Ignition Composition Processing

3.1.1 Ignition Composition Requirements

3.1.1.1 Ignition Composition

3.1.1.1.1 Ignition Composition Materials

3.1.1.1.2 Formulation

3.1.2 Igniter Material Blending Procedure

3.1.2.1 Mixing

3.1.2.2 Drying

3.1.2.3 Storage

3.1.2.4 Particle Size Variation

3.1.3 Workmanship

3.1.4 Loading Procedure

3.1.5 Ignition Composition Burn Rate

3.1.6 Magnesium Hydroxide Mg(OH)2

3.1.7 Pellet Ignition Test

3.2 Grain Processing

3.2.1 Grain Composition Requirements

3.2.1.1 Grain Composition

3.2.1.1.1 Grain Composition Materials

3.2.1.1.2 Formulation

3.2.2 Grain Composition Burn Rate

3.2.3 Grain Material Blending Procedure

3.2.3.1 Mixing

3.2.3.2 Drying

3.2.3.3 Storage

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3.2.3.4 Particle Size Variation

3.2.4 Extruding Flare Grain Plank

3.2.5 Grain Cutting & Machining

3.3 Payload Assembly Processing

3.3.1 Nozzle Installation

3.3.2 Grain Assembly

3.3.3 Payload Assembly

3.3.4 Payload Epoxy Cast, and Cure

3.3.5 Igniter Assembly

3.3.6 Flare Assembly

3.3.7 IR Test Unit

4. VERIFICATION

4.1 Responsibility for Inspection

4.2 Tests

4.2.1 Grain Composition Burn Rate Test

4.2.2 Ignition Composition Burn Rate Test

4.2.3 Magnesium Hydroxide Test

4.2.4 Igniter Wire Spring Retention Test

4.2.5 Pellet Ignition Test

5. PACKAGING

This section is not applicable to this specification

6. NOTES

6.1 Definitions

6.1.1 Flare

6.1.2 Cognizant Design Authority

Tables

TABLE I. Minimum Materials Acceptance Criteria and Test Methods for Composition

Materials

Figures

Figure 1. Payload Epoxy Casting Illustrations

Figure 2. Grain and Ignition Composition Burn Rate Test Specimen

1. SCOPE

1.1. Scope. This specification documents the process requirements used for the manufacture of the MJU-76/B FLARE, COUNTERMEASURE. The processing instruction herein documents the processes used during development to meet the performance requirements of PRF 201825310. These processes herein have been found to be acceptable however, they are not limited to the only processes that could be acceptable. Therefore, deviation from the following processes, that have been demonstrated acceptable, shall be presented for authorization to the Cognizant Design

Authority IAW contract CDRL’s. This document is unclassified.

1.2. Definitions. The meanings of the terms used in this specification are listed in 6.1.

2. APPLICABLE DOCUMENTS

2.1. Government Documents. The following documents of the issue in effect on date of invitation for bids or request for proposal form a part of the specification to the extent specified herein. In the event of conflict between the documents referenced herein and the contents of this specification, the contents of this specification shall be considered a superseding requirement.

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: AFLCMC/EBHCC, 6033

Elm Lane, Hill AFB, Utah 84056-5819 or AFLCMC/EBHCC.CMFLARES@us.af.mil by using the Specification Change Notice (SCN) DD Form 1696 or other document.

2.1.1. Standards

MIL-STD-331 Rev D Fuzes, Ignition Safety Devices and other related components, Environmental and Performance Tests for.

MIL-STD-810 Rev H Environmental Engineering Considerations and Laboratory Tests

MIL-STD-1168 Ammunition Lot Numbering and Ammunition Data Card

MIL-STD-1171 Energetic Material Description Sheets and Propellant Loading

Authorization Sheets

MIL-STD-1916 DOD Preferred Methods for Acceptance of Product

DOD-4145.26-M DOD Contractor’s Safety Manual for Ammunition and Explosives

2.1.2 Drawings. All applicable drawings are delineated within DL 201825310 Cage Code

98747 and applicable contract documents.

(Copies of standards, drawings, and publications required by contractors in connection with specific acquisition functions should be obtained from the Contracting Activity or as directed by the Contracting Activity)

3. REQUIREMENTS

NOTE: Anything in Italics font (example) should be considered a recommendation.

NOTE: Processing Environment. Processing environment should be between 60°F – 80°F and less than 60% Relative Humidity for entire manufacturing process, where possible, required where noted. Processing environment of < 40% relative humidity is an increased

‘SAFETY HAZARD’ and is ‘NOT’ recommended due to increased risk of electrostatic discharge.

3.1 Ignition Composition Processing.

3.1.1 Ignition Composition Requirements.

3.1.1.1 Ignition Composition. The ignition composition is used to press a single ignition pellet within the MJU-76/B igniter assembly IAW drawing 201825315. This assembly when used in the MJU-76/B flare shall ignite the flare within the stated requirements of

PRF 201825310.

3.1.1.1.1 Ignition Composition Materials. The materials used to blend the ignition composition shall meet the individual materials requirements stated in Table I. The supplier's manufacturing process shall ensure that the material chemical composition is homogeneous within the limits of Table I.

3.1.1.1.2 Formulation. The materials per 3.1.1.1.1 shall be formulated as shown in

Drawing 201825344. Suggested to follow essential processing parameters provided below and tested as stated herein. The composition is acceptable when the characteristics of this specification are met. It has been found that composition tested

IAW 3.1.5, 3.1.6, and 3.1.7 have been found to provide acceptable results.

3.1.2 Ignition Material Blending Procedure. The following blending procedure has been found to provide acceptable results.

3.1.2.1 Mixing. The following process using a Cowles hi-shear impellor type mixer has been used for mixing:

a. Dissolve copolymer into acetone to make an approximate 25% copolymer solution by weight. (NOTE: Acetone may be added as desired during mixing cycle to facilitate mixing and provide a proper consistency.)

b. Transfer the copolymer solution into mixer and start mix cycle at high blade speed. (NOTE: Correct blade speed is obtained when the ingredients form a vortex in the container and all ingredients are in a state of flow.) Mixer should run continuously until first wash is complete.

c. Add PTFE molding material slowly and mix 2 to 5 minutes after addition is complete.

d. Add Atomized Magnesium slowly and mix 10 minutes minimum after addition is complete.

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e. Precipitation period: with mixer at high blade speed, add iso-hexane slowly until mix begins to thicken. Stop the addition of iso-hexane and let mixer run 2 minutes.

f. Perform first wash by adding until a minimum of 2.5 parts iso-hexane to one part acetone by volume has been added and then “wash” for 10 minutes minimum.

g. Stop mixer and allow ingredients to settle into the bottom of the mixing container and then decant liquids.

h. Perform second wash by adding a minimum of 0.8 parts of iso-hexane and resume mixing for 10 minutes minimum wash.

i. Stop mixer and allow ingredients to settle into the bottom of the mixing container and then decant liquids.

3.1.2.2 Drying. The following process is used to dry the mix:

a. Spread the wet composition into a shallow pan to air dry in the hood or well-ventilated area for 1 hour minimum.

b. Dry in an oven at 150°F ± 10°F for 8 hours minimum or until fully dry

(process verified).

3.1.2.3 Storage. Store the composition in a sealed container with an indicator card and desiccant IAW MIL-D-3464, Type I. Size of container and desiccant unit per container is optional.

3.1.2.4 Particle Size Variation. Particle size of the final composition may be varied by adjusting:

a. The initial acetone amount before adding iso-hexane. (NOTE: maintain a 2.5 minimum part iso-hexane to one part acetone by volume for first wash.)

b. Blade speed.

c. Initial addition rate of iso-hexane.

3.1.3 Workmanship. The ignition composition shall be a continuous homogeneous mix free of contamination.

3.1.4 Loading Procedure. The ignition composition shall be loaded with the following process unless an alternate method is approved by the Cognizant Design Authority. The igniter body part number 201825318 shall be loaded with ignition composition part number 201825344 as follows:

a. Inspect an igniter body to ensure it is free of dirt, grease, chips, or any foreign materials prior to loading.

b. Dry ignition composition in an oven at 150°F ± 10°F for 3 hours minimum and begin pressing within 48 hours of drying. Ignition composition shall be stored in a sealed desiccated container when not in use during the aforementioned 48 hours.

c. Load 680 milligrams minimum to 720 milligrams of ignition composition in cavity of the body and level. Press composition in environmental conditions IAW Section 3.

d. 1250 ± 50 pounds dead weight with a dwell time of 3 to 7 seconds for the consolidation of ignition composition into a body.

e. Igniter body shall be 100% visually inspected and found free of cracks or deformities.

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f. Loose igniter composition shall be removed in a manor to not disturb the face of the pressed composition.

g. Pressed composition shall be flush or below flush of igniter body top surface and meet all requirements after completed.

h. If storage is required after pressing, store item in sealed desiccated container.

i. The presence of a waffle configuration is required. Waffle configuration of ram with a

90° by 0.03 in. peak-to-peak waffle pattern surface to aid pellet ignition has been found to provide satisfactory ignition of ignition composition and is highly recommended.

3.1.5 Ignition Composition Burn Rate. The required burn time of a test pellet configured and tested per Section 4.2.2 below shall be 1.3 sec./inch MIN to 1.8 sec./inch.

MAX. Dried compositions may be cross blended to obtain burn time and output specified herein.

3.1.6 Magnesium Hydroxide Mg(OH)2. The ignition composition shall be measured for presence of Magnesium Hydroxide Mg(OH)2 prior to being pressed into ignition pellets when tested in accordance with 4.2.3. Recommend also verifying Mg(OH)2 after pressing ignition pellets to validate storage and processing environment.

3.1.7 Pellet Ignition Test. Each blend of ignition composition shall be tested for ignition pellet ignitability, slider actuation and ejection velocity in a full up flare using either a full flare as part of acceptance or a test sample using live or inert grain per drawing 201825310, it has been found that the procedures IAW section 4.2.5 provide good indication that the ignition composition is acceptable. The test sample will be initiated using a standard impulse cartridge per PRF 201825310. It is recommended that this test be performed for each blend of composition prior to full production with an inert grain.

3.2. Grain Processing.

3.2.1 Grain Composition Requirements.

3.2.1.1 Grain Composition. The grain composition is used to form the grain within the

MJU-76/B payload assembly IAW drawing 201825313. This assembly when used in the

MJU-76/B flare shall meet the performance requirements IAW PRF 201825310.

3.2.1.1.1 Grain Composition Materials. The materials used to blend the grain composition shall meet the individual materials requirements stated in Table I. The supplier's manufacturing process shall ensure that the material chemical composition is homogeneous within the limits of Table I.

3.2.1.1.2 Formulation. The materials per 3.2.1.1.1 shall be formulated as shown in

201825346, following essential processing parameters provided below and tested as stated herein. The composition is acceptable when the characteristics of this specification are met and the flare meets the requirements of PRF 201825310.

Approximate percentages of magnesium type may be varied to obtain the burn time and output specified, while maintaining overall magnesium composition values shown on 201825346.

3.2.2 Grain Composition Burn Rate. The burn time of a test pellet configured and tested per Section 4.2.1 below. A linear burn rate of 6.5 sec./inch to 8.0 sec./inch using

G-10 (20157210) and 4.5 sec./inch to 5.5 sec./inch using N-590 (has been found to

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demonstrate a composition that is considered acceptable. Dried compositions may be cross blended to obtain burn time and output specified herein.

3.2.3 Grain Material Blending Procedure. The following blending procedure has been found to provide acceptable results; however, alternate blending procedures may be approved by the Cognizant Design Authority.

3.2.3.1 Mixing. The following process using a Cowles hi-shear impellor type mixer has been used for mixing:

a. Dissolve acetone into copolymer to make an approximate 25% copolymer solution by weight.

b. Transfer the copolymer solution into mixer and start mix cycle at high blade speed. (NOTE: high or correct blade speed is obtained when the ingredients form a vortex in the container and all ingredients are in a state of flow.) Mixer should run continuously until first wash is complete.

c. Add PTFE molding material slowly and mix 2 to 5 minutes after addition is complete.

d. Add Atomized Magnesium slowly and mix 10 minutes minimum after addition is complete.

e. Precipitation period: with mixer at high blade speed, add iso-hexane slowly until mix begins to thicken. Stop the addition of iso-hexane and let mixer run 2 minutes.”

f. Perform first wash by adding until a minimum of 2.5 parts iso-hexane to one part acetone by volume has been added and then “wash” for 10 minutes minimum.

g. Stop mixer and allow ingredients to settle into the bottom of the mixing container and then decant liquids.

h. Perform second wash by adding a minimum of 0.8 parts of iso-hexane and resume mixing for 10 minutes minimum wash.

i. Stop mixer and allow ingredients to settle into the bottom of the mixing container and then decant liquids.

j. Acetone may be added as desired during mixing cycle to facilitate mixing and provide a proper consistency. Maintain a min of 2.5 parts iso-hexane to one part acetone by volume during mixing/wash cycle.

3.2.3.2 Drying. The following process is used to dry the mix:

a. Spread the wet composition into a shallow pan to air dry in the hood or well-ventilated area for 1 hour minimum.

b. Dry in an oven at 150°F ± 10°F for 12 hours minimum or until fully dry

(process verified).

3.2.3.3 Storage. Store the composition in a sealed container with an indicator card and desiccant IAW MIL-D-3464, Type I. Size of container and desiccant unit per container is optional.

3.2.3.4 Particle Size Variation. The composition particle size may be varied by adjusting:

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a. The initial acetone amount before adding iso-hexane. (NOTE: maintain a 2.5 part iso-hexane to one part acetone by volume for first wash.)

b. Blade speed.

c. Initial addition rate of iso-hexane.

TABLE I

Minimum Materials Acceptance Criteria and Test Methods for Composition Materials

Material Material Requirement Test Method (Note 1)

Atomized Magnesium, -

Drawing 201416446 IAW 201416446-01 (Note 1)

Magnesium Powder MIL-DTL-382, Type III, Gran

IAW MIL-DTL-382 (Note 1 & 2)

Metal Powders MIL-DTL-14067, Type I, 200/325

IAW MIL-DTL-14067 (Note 1)

PTFE Molding Material ASTM D4894, Type III IAW ASTM D4894 except (Note

1, 3 & 4)

PTFE, G10 Drawing 20157210 IAW 20157210-01 (Note 1)

PTFE, N Series (N590) Drawing 20156981 IAW 20156981-03 (Note 1)

PTFE, N Series (N600) Drawing 20156981 IAW 20159681-01 (Note 1)

Copolymer Drawing 20156942 IAW 20156942-01 or -02 (Note 1)

Acetone ASTM D329 (Note 1)

Iso-Hexane Drawing 20156982 IAW 20156982-01 (Note 1)

Notes:

(1) Material compliance will be demonstrated on a Certificate of Compliance or Certificate of Analysis upon flare lot acceptance. All sieves used shall be IAW

ASTM E11

(2) Magnesium powder shall meet the requirements of MIL-DTL-382, Type III, Gran 16 except:

a. 100% min thru 100 sieve

b. 5% max thru 100 sieve and retained on 170 sieve

c. 20% max thru 170 sieve and retained on 200 sieve

d. 50 - 80% thru 200 sieve and retained on 325 sieve

e. 10 - 30% thru 325 sieve

(3) PTFE Molding Material shall meet the requirements of ASTM D4894 except:

a. See drawing 201825344 for exceptions regarding Average Bulk Density and Particle Size

Average Diameter

(4) PTFE 7AX, manufactured by DuPont, Special Polymers Division, Wilmington, DE has been found to meet the requirements of PTFE Molding material

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3.2.4 Extruding Flare Grain. The following flare grain extrusion process has been found to be acceptable. Typically grains are extruded into planks. A plank is defined as the extruded composition meeting dimensions in 201825335, before it is cut/machined to grain length and shape. Typical plank length is 20 - 24 inches. Use the following grain/plank extrusion process:

a. Preheat composition at 150° ± 10°F for 8 hours minimum prior to extruding.

b. Heat the extrusion charge cylinder and extrusion die to 190° - 195°F

c. Extruding at a rate of 8 - 12 inches of plank per minute has produced satisfactory results.

d. A normalizing procedure can be used to relieve internal stresses to the plank caused by the extruding process:

1- Let extruded plank lay for 8 hours at 60° - 80°F prior to normalizing.

2- Normalize plank for 20 hours min at 150° ± 10°F.

3- Let normalized plank lay for 3 hours at 60° - 80°F prior to cutting into lengths.

3.2.5 Grain Cutting & Machining.

Reference drawing 201825335

a. Components shall be free from dirt, grease, chips, and other extraneous materials, immediately prior to assembly. Fibers extending from surface due to extruding, cutting, or machining are allowed as long as form, fit, and function are not affected. Items shall be processed IAW Section 3 Processing Environment Note.

b. The grain is formed from the extruded plank by cutting and machining to the grain contour in accordance with drawing 201825335. The internal core of the grain is a tool-controlled feature and does not need to be directly inspected, the core is formed with an approved extrusion die tool.

c. If Grain Assembly (Section 3.3.2) is not achieved within one hour, this item shall be stored in a desiccated container.

3.3. Payload Assembly Processing.

3.3.1 Nozzle Installation.

Reference drawing 201825313

a. Components shall be free from dirt, grease, chips, and other extraneous materials, immediately prior to assembly. Items shall be processed IAW Section 3 Processing

Environment Note.

b. Install O-ring onto nozzle as shown on drawing 201825313. Clean payload body inside with acetone and then apply thin coat of mold release (DEV24133) to the inside of the payload body. Cleaning of the payload body inside can occur upon receiving component.

Insert the nozzle with O-ring into the body and seat the nozzle into the body cutout as shown in 201825313.

3.3.2 Grain Assembly.

Reference drawing 201825313

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a. Components shall be free from dirt, grease, chips, and other extraneous materials, immediately prior to assembly. Fibers extending from surface due to extruding, cutting, or machining are allowed as long as form, fit, and function are not affected. Items shall be IAW

Section 3 Processing Environment Note.

b. Press double sided tape (DEV21008), to forward end of the machined grain and/or the

201825337 grain plug per the requirements of 201825313 and 201825335.

c. Attach 201825337 grain plug, to the end on grain, until seated.

d. Place grain seal to the aft end of the machined grain as shown in drawing 201825313 and

201825335.

e. Grain assembly can be immediately loaded into payload assembly. If payload assembly

(Section 3.3.3) is not achieved within one hour, this item shall be stored in a desiccated container.

3.3.3 Payload Assembly.

Reference drawing 201825313

a. Components shall be free from dirt, grease, chips, and other extraneous materials, immediately prior to assembly. Items shall be processed IAW Section 3 Processing

Environment Note.

b. Insert grain with grain plug and grain seal, into open end of payload body tube with nozzle, aft end (with grain seal) first. Apply force, 40 lbs max, to grain with grain plug, to ensure grain seats into nozzle as shown in drawing 201825313.

c. Insert wave spring, into body tube on top of grain plug and seat nose cap with O-ring, installed into top of payload body tube and nozzle. Hold assembly at 20 - 70 lbs (excessive force may cause undesired deformities) and apply 8-point crimp, evenly spaced, to secure into place (see 201825313) using a quarter inch pin with a 90° angle with a 0.028 inch spherical radius point. The force to separate aluminum body tube with nozzle, and nose cap, shall be 600 lbs. minimum when the force is applied at a rate of 1.0 ± 0.1 in/min. Retention may be verified using inert samples of body tube and nose cap. Report results IAW PRF

201825310.

d. Inspect the 0.525 minimum dimension per 201825313, 100% inspection to ensure grains are fully seated.

e. If Payload Epoxy Cast and Cure (Section 3.3.4), is not achieved within one hour, the assembly shall be stored in a desiccated container.

3.3.4 Payload Epoxy Cast, and Cure.

a. Components shall be free from dirt, grease, chips, and other extraneous materials, immediately prior to assembly. Items shall be IAW Section 3 Processing Environment Note.

b. Install funnel into the payload nose cap until it bottoms out in counter bore as shown in illustration 1 of Figure 1.

c. Place assembly, into oven at 150°F ± 10°F for a minimum of 2 hours. (Heated payload assembly enhances epoxy flow).

d. Epoxy blending procedure:

1) Weigh out the epoxy resin and polyamide curing agent ingredients in a 70 ± 3% epoxy resin to 30 ± 3% polyamide by weight ratio respectively.

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2) Place polyamide curing agent, into 150 ± 10°F oven for 2-8 hours to reduce viscosity. Do not heat epoxy resin.

3) Blend epoxy resin and heated curing agent, together until a homogeneous mixture is obtained, while minimizing trapped air.

4) Use immediately after mixing to take advantage of lower viscosity.

e. Remove body assembly from oven and orient vertically as shown in illustration 2 of

Figure 1. Assembly shall be filled while still warm.

f. Epoxy fill method:

1) Pour blended epoxy into funnel cavity, filling the funnel with 11 – 12 grams

(10.11 - 11.03 milliliters) of epoxy (see illustration 2 of Figure 1). Epoxy will start draining into voids inside Payload assembly. No epoxy is allowed on unit exterior, clean any spillage immediately.

2) After adding epoxy to Payload assembly, subject assembly to 17-25 in. Hg vacuum for 45 - 75 seconds. Bubbles of air will be pulled out of unit through the epoxy in the funnel indicating the unit is filling with epoxy (adjust vacuum level to minimize foaming as required).

3) Turn off vacuum for a minimum of 30 seconds.

4) Repeat step 2 and step 3 until three vacuum cycles have been performed.

5) After vacuum procedure, keep units oriented vertically. Leave units in this orientation until fully cured (recommended 16 hours minimum at 85°F - 100°F). This allows bubbles of trapped air to flow upward and out the funnel hole as epoxy cures.

g. If epoxy leakage occurs at the nozzle location, either through or around, the unit is defective and shall not be used. 100% inspection required.

h. If epoxy leakage occurs at the funnel spout location, where it is pressed into the body tube assembly, and epoxy is only on the top of the Nose Cap, clean with a flat blade, if epoxy leakage occurs down the side of the Nose Cap or onto the Body Tube, the unit is defective and shall not be used. 100% inspection required.

i. After fully cured (process verification), cut funnel off Payload assembly at the spout location with the nose. The part of the spout left in unit after cutting will remain with unit

(see illustration 3 of Figure 1). Verify the epoxy/spout height and nozzle height are within the dimensions shown on drawing 201825313 (see illustration 4 of Figure 1).

j. Payload assembly with epoxy shall be dried in oven at 150 ± 10°F for 3 - 120 hours.

k. If Flare Assembly (Section 3.3.6), on 201825310, is not achieved within one hour, the assembly shall be stored in a desiccated container.

Figure 1 Payload Epoxy Casting Illustrations

3.3.5 Igniter Assembly.

Reference drawing 201825315

a. For the -30 assembly (body w/ignition composition), load ignition composition into igniter body IAW 3.1.5.

b. Install wire spring connector into igniter coupler slot until seated.

c. Insert compression spring into slider. Then insert assembled slider and compression spring into body w/ignition composition.

d. Orient and place igniter body w/ slider onto igniter coupler with wire spring connector.

e. Seat piston onto body w/ignition composition, and coupler, and secure with screws.

Torque to 3 – 5 inch lbs until screws are fully seated without damage to components.

f. After assembly, slider shall be functioned and move without binding when compressed and released. 100% inspection is required.

g. Igniter assembly shall be dried in oven at 150F ± l0°F for 3 - 120 hours.

h. If Flare Assembly (Section 3.3.6) on 201825310 is not achieved within one hour, the assembly shall be stored in a desiccated container.

0.295 MIN

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3.3.6 Flare Assembly.

Reference drawing 201825310

a. Components shall be free from dirt, grease, chips, and other extraneous materials, immediately prior to assembly. Items shall be IAW Section 3 Processing Environment

Note.

b. Ensure drying requirements for payload assembly are achieved prior to flare assembly.

c. Ensure warning marking is present and legible on opposing sides of payload assembly body tube, before loading assembly into case. See drawing 201825313 or 201825330 for warning marking. Laser marking has been found to provide adequate marking. Sample marking to be approved by Cognizant Design Authority. 100% inspection required.

Note: Warning label can be applied at any point prior to Flare Assembly.

d. For the -30 assembly (payload assembly with igniter assembly), align wire spring connector contained in igniter assembly with retaining notches in the nozzle contained in payload assembly, then snap into place. Once igniter assembly is installed, if it is detached, both the igniter assembly and payload assembly is considered defective unless otherwise approved from the Cognizant Design Authority.

e. Insert -30 assembly into case, with slider depressed. Then insert compression pad into case. Payload insertion funnel (30003) SA3976AS140 has been found to aid the insertion of the payload assembly with igniter assembly into the case.

f. Apply a liberal coat of O-ring grease onto square seal, and install onto end cap.

g. Insert end cap with square seal into case and crimp case corners to the end cap chamfers to secure assembly. A force range to separate the end cap from the case shall be 150-300 lbs when force is applied at a rate of 1.0 ± .1 in/min. Crimper (30003) SA3976AS169 has been found to provide a satisfactory crimp. Retention may be verified using inert samples of case and end cap. Report results IAW PRF 201825310.

h. Apply a light coat of O-ring grease to O-ring, impulse cartridge, and O-ring groove in case and insert O-ring, impulse cartridge into O-ring groove.

3.3.7 IR Test Unit.

Reference drawing 201825350

For use as required when transported across public property.

a. Components shall be free from dirt, grease, chips, and other extraneous materials, immediately prior to assembly. Items shall be IAW Section 3 Processing Environment

Note.

b. Ensure drying requirements of payload assembly, end cap and compression pad are achieved prior to assembly.

c. Insert IR spacer into case until seated at the bottom.

d. Insert payload assembly into case until seated against IR spacer.

e. Apply a liberal coat of O-ring grease onto square seal and install onto end cap.

f. Insert compression pad and end cap with square seal into case.

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g. Secure end cap to case using 3M anti-static utility tape 40, with minimum wrinkles and the circumference tape applied last.

4. VERIFICATION

4.1 Responsibility for Inspection. Unless otherwise specified in the contract or delivery order, the contractor is responsible for the performance of all inspection requirements and testing as specified herein. Except as otherwise specified in the contract or delivery order, the contractor may use their own or any other facilities suitable for the performance of the inspection requirements specified herein, once said facility is approved by the Cognizant Design Authority.

The government reserves the right to perform any of the inspections set forth in the specifications (PRF 201825310 and this document) where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements.

4.2 Tests.

4.2.1 Grain Composition Burn Rate Test. Reference (SA3976AS201)

The loose grain composition, blended per this specification, shall be tested for burn rate by forming a pellet approximately 0.75 inches in diameter and long enough to contain 14 ± 0.5 grams of composition. The following, Figure 2, illustrations and process documented below has been found to provide adequate test results, however, alternate test samples may be approved by the Cognizant Design Authority.

a. Grain composition, shall be conditioned for a minimum of 3 hours at 140°F - 170°F and pressed while at 140°F - 170°F.

b. Preheat sample tooling for a minimum of 3 hours at 140°F - 170°F.

c. Remove tooling from oven and a thin layer of Stoner mold release agent (part# S236) may be applied to the ram waffle pattern of the tooling, however, do not spray mold release into barrel of tooling.

d. Place conductive plastic pellet tube (made of ESD C700 plastic) into tooling barrel, and onto a supporting base.

e. Remove Grain composition sample from oven and pour 14.0 ± 0.5 grams into the tool barrel. Then press material into the plastic tube at 3740 ± 110 PSI (1650 ± 50 lb. dead load) with a dwell time of 10 ± 2 Seconds. Note: press at the preconditioned temperature of 140°F

- 170°F using a ram with a 110° by 0.03 in. peak-to-peak waffle pattern surface to aid pellet in ignition.

f. Resulting pressed test specimen shall have no cracks or deformities after pressing.

g. Loose composition shall be removed by light brushing. Care should be taken not to disturb the face of waffle configuration.

Note: If storage of test specimens are required, then store in a desiccated container.

h. Pellet shall be at a temperature of 75°F ± 25°F at time of burning.

i. Burn time shall be recorded using video or other suitable means.

Finished component should permit compliance with linear burn rate requirements in Section

3.2.2 herein.

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4.2.2 Ignition Composition Burn Rate Test. Reference (SA3976AS201)

The loose ignition composition, blended per this specification, shall be tested for burn rate by forming a pellet approximately 0.75 inches in diameter and long enough to contain 12 ± 0.5 grams of composition. The following, Figure 2, illustrations and process documented below has been found to provide adequate test results, however, alternate test samples may be approved by the Cognizant Design Authority.

Preparation and testing of the test item is as follows:

a. Ignition composition, shall be conditioned for a minimum of 3 hours at 140°F - 170°F and pressed while at 140°F - 170°F.

b. Preheat sample tooling for a minimum of 3 hours at 140°F - 170°F.

c. Remove tooling from oven and a thin layer of Stoner mold release agent (part# S236) may be applied to the ram waffle pattern of the tooling, however, do not spray mold release into barrel of tooling.

d. Place conductive plastic pellet tube (made of ESD C700 plastic) into tooling barrel, and onto a supporting base.

e. Remove ignition composition sample from oven and pour 12.0 ± 0.5 grams into the tool barrel. Then press material into the plastic tube at 3740 ± 110 PSI (1650 ± 50 lb. dead load) with a dwell time of 10 ± 2 Seconds. Note: press at the preconditioned temperature of 140°F

- 170°F using a ram with a 110° by 0.03 in. peak-to-peak waffle pattern surface to aid pellet in ignition.

f. Resulting pressed test specimen shall have no cracks or deformities after pressing.

g. Loose composition shall be removed by light brushing. Care should be taken not to disturb the face of waffle configuration.

Note: If storage of test specimens are required, then store in a desiccated container.

h. Pellet shall be at a temperature of 75°F ± 25°F at time of burning.

i. Burn time shall be recorded using video or other suitable means.

Finished component should permit compliance with linear burn rate requirements in Section

3.1.2 herein.

Figure 2 Grain and Ignition Composition Burn Rate Test Specimen

4.2.3 Magnesium Hydroxide Test. Each blend of utilized ignition composition shall be tested for the presence of Mg(OH)2 (Magnesium Hydroxide). Report results IAW PRF

201825310.

The thermogravimetric analysis (TGA) process is as follows:

a. Obtain 5-20 milligram sample of ignition composition.

b. Place sample in ceramic pan (preferred), open pan required.

c. Run ultra-high purity nitrogen purge at the flow rate recommended for instrument.

d. Ramp the temperature from 50°C to 500°C at 20°C per minute.

e. Record percent weight loss from intrinsic moisture (50°C-150°C).

f. Record percent weight loss from magnesium hydroxide decomposition (250°C-425°C)

g. Calculate percent of magnesium in composition converted to Mg(OH)2.

NOTE: See below sample calculation for methods of calculating magnesium conversion:

Where:

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[B] Sample Mass (mg) = Mass of sample loaded into pan This is assumed to contain Mg, Teflon, Viton, water and volatiles, Mg(OH)2

[C] Intrinsic moisture % = % of sample that is lost from 50-150 oC; this is water and other volatiles that evaporate in this temperature range

[D] Hydroxide H2O % = % of sample that is lost from 250-425 oC due to decomposition reaction:

Mg(OH)2 (s) --> MgO (s) + H2O (g)

[E] Moles H2O = moles of water from decomposition reaction:

= 𝑆𝑎𝑚𝑝𝑙𝑒 𝑀𝑎𝑠𝑠(𝑚𝑔) ( ℎ𝑦𝑑𝑟𝑜𝑥𝑖𝑑𝑒 𝐻2𝑂%

100% 𝑆𝑎𝑚𝑝𝑙𝑒 𝑚𝑜𝑙 𝐻2𝑂

18000 𝑚𝑔 𝐻2𝑂

[F] Moles Mg(OH)2 = moles of magnesium hydroxide that would evolve the water from decomposition reaction:

= 𝑀𝑜𝑙𝑒𝑠 𝐻2𝑂( 𝑚𝑜𝑙 𝑀𝑔(𝑂𝐻)2

𝑚𝑜𝑙 𝐻2𝑂

[G] Mass Mg(OH)2 (mg) = mass of magnesium hydroxide that decomposed

= 𝑀𝑜𝑙𝑒𝑠 𝑀𝑔(𝑂𝐻)2(

58,000 𝑚𝑔 𝑀𝑔(𝑂𝐻)2

𝑚𝑜𝑙 𝑀𝑔(𝑂𝐻)2

[H] Mass Mg in Mg(OH)2 (mg) = mass of magnesium that comprises magnesium hydroxide

= 𝑀𝑎𝑠𝑠 𝑀𝑔(𝑂𝐻)2(𝑚𝑔)(

𝑚𝑚𝑜𝑙 𝑀𝑔(𝑂𝐻)2

58 𝑚𝑔 𝑀𝑔(𝑂𝐻)2

𝑚𝑚𝑜𝑙 𝑀𝑔 𝑚𝑚𝑜𝑙 𝑀𝑔(𝑂𝐻)2

24 𝑚𝑔 𝑀𝑔 𝑚𝑚𝑜𝑙 𝑀𝑔

[I] Original Mass Frac Mg = magnesium assumed to be in composition, expressed as mass fraction

[J] Original Mass Mg (mg) = magnesium in original sample. The mass of intrinsic moisture (water and volatiles) and magnesium hydroxide are first subtracted from the sample mass, then the mass of magnesium in the magnesium hydroxide is added back. That leaves a sample comprised of Mg, Teflon and Viton. This is multiplied by the Original Mass Frac Mg to give the total mass of magnesium

[K] Mg Convert to Mg(OH)2 % = the percentage of the original magnesium that has been converted to magnesium hydroxide; percent degradation of the sample.

𝑀𝑎𝑠𝑠 𝑀𝑔 𝑖𝑛 𝑀𝑔(𝑂𝐻)2

𝑂𝑟𝑖𝑔𝑖𝑛𝑎𝑙 𝑀𝑎𝑠𝑠 𝑀𝑔 ) ∗ 100%

4.2.4 Igniter Wire Spring Retention Test.

Reference drawing 201825361 (Note: refer to igniter coupler 201825316 and nozzle 201825332 for mating surface contours).

a. Install wire spring connector into metal coupler until seated.

b. Screw coupler and wire spring connector to retainer using pan head screws.

c. Insert nozzle into the base until seated.

d. Align wire spring connector, with retaining notches of the nozzle in the orientation shown on 201825361. Push coupler test assembly onto the metal nozzle until it snaps into place.

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e. Insert push rod into the metal nozzle until seated.

f. Insert spring retention fixture into a compression test machine and test the igniter retention at a rate of 1 inch/min to record the force to push the coupler test assembly off the nozzle.

g. Remove the spring retention fixture from the compression test machine. Remove the push rod and disassemble the retainer from the coupler test assembly. Insert coupler and wire spring connector onto the spring remover assembly. Use a flat head screwdriver to remove wire spring connector.

This is a destructive test. Report test results IAW PRF 201825310.

4.2.5 Pellet Ignition Test.

a. One hundred "igniter bodies", 201825318, shall be loaded IAW DTL 201825313 with the batch or blend of ignition composition to be qualified.

b. The resulting "igniter body with ignition composition", DTL 201825313, shall be assembled into one hundred "igniter assemblies", 201825315.

c. The "igniter assemblies" shall be assembled onto inert, or dummy grains and loaded as full-up assemblies in accordance with drawing 201825310.

d. The 100 full-up assemblies shall be subdivided into two groups for testing and static functioned as follows:

1. A group of 80 full-up assemblies shall be temperature conditioned at -65°F ± 5°F.

2. A group of 20 full-up assemblies shall be temperature conditioned at 171°F ± 5°F.

3. A CCU-145/A or equivalent impulse cartridge shall be used.

4. Each full-up assembly shall be temperature conditioned for a minimum of four hours with the impulse cartridge installed.

5. Each group of full-up assemblies shall be tested within ten minutes of removal from the conditioning chamber and fired using an AN/ALE-40 or equivalent dispenser system.

e. The full-up assemblies shall be evaluated as follows:

1. All 100 full-up assemblies shall have an ejection velocity greater than 60 ft/s.

2. Each of the 100 full-up assemblies shall have a slider that slid to the out position.

3. Each of the 100 full-up assemblies shall have an ignition pellet that lit.

5. PACKAGING

This section is not applicable to this specification.

6. NOTES

6.1 Definitions.

6.1.1 Flare. The MJU-76/B is an expendable infrared (IR) countermeasure for aircraft applications. The payload assembly, when launched from an aircraft, will attain a trajectory similar to the aircraft’s and will provide an IR output to improve the aircraft’s capability to counter or decoy IR threats.

The MJU-76/B has approximately a 1” x 1” square cross section and is approximately 8” long. It is ejected from an infrared countermeasure magazine (MJU-11/A, MJU-33/A or equivalent) housed within an infrared countermeasure dispenser (ALE-40, -45, -47, or equivalent). The dispenser transmits a firing pulse into the pyrotechnic squib (impulse

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cartridge; CCU-145, BBU-35 or equivalent) installed in the base end of the flare case. The impulse cartridge ejects the payload assembly from the flare case. The impulse cartridge lights a pyrotechnic pellet within the igniter. Once the aft end of the flare clears the case, the flame from the ignition pellet is exposed to the main pyrotechnic grain of the payload assembly. The main flare grain ignites. Ignition of the main pyrotechnic grain displaces the igniter and provides thrust and infrared energy (intensity).

6.1.2 Cognizant Design Authority. The term “Cognizant Design Authority” is defined as the Government Program Office that has current design responsibility as noted by the current

CAGE CODE of the Technical Data Package. This TDP is controlled by AFLCMC/EBHCC

CAGE CODE 98747.