tb 3-4240-341-20 technical bulletin installation...

TB 3-4240-341-20

TECHNICAL BULLETIN

INSTALLATION AND FITTING INSTRUCTIONSFOR

M45 MASK THERMOPLASTIC LINER

DISTRIBUTION STATEMENT C : Distribution authorized to U.S. Government agencies and theircontractors to protect technical or operational information. This determination was made on1 September 1994. Other requests for this document will be referred to: Commander, USA SBCCOM,ATTN: AMSSB-RBD-B, 5183 Blackhawk Road, Aberdeen Proving Ground, MD 21010-5424.

DESTRUCTION NOTICE : Destroy by any method that will prevent disclosure of contents orreconstruction of the document.

HEADQUARTERS, DEPARTMENT OF THE ARMY

30 JULY 1999

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WARNING SUMMARY

This warning summary includes general safety precautions and instructions that must be understood andapplied during the operation and maintenance of this system/equipment to ensure personnel againstinjury, death, or long-term health hazards. A summary of safety and hazardous material warnings thatshould be heeded in conduct of operation and maintenance is provided below.

WARNING

Proper fitting of the helmet with the M45 thermoplastic liner is essential to the functioning of the HGU-56/P when used with the M45 Mask, all of its modules, and the safety of the operator. Take as much timeas necessary to install and fit the kit properly. Use extreme care in checking fit.

Handle the heated thermoplastic liner carefully; the plastic layers will be hot. Touch the fabric cover only.Wear gloves if necessary.

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LIST OF EFFECTIVE PAGES/WORK PACKAGES

Date of issue for the original manuals is:

Original .. 0 .. 30 Jul 99

TOTAL NUMBER OF PAGES FOR FRONT AND REAR MATTER IS 5 AND TOTALNUMBER OF WORK PACKAGES IS 5, CONSISTING OF THE FOLLOWING:

Page/WP *Change Page/WP *ChangeNo. No. No. No.

Title 0Warnings 0A 0B Blank 0i - ii 0WP 0001 00 (2 pgs) 0WP 0002 00 (3 pgs) 0WP 0003 00 (4 pgs) 0WP 0004 00 (3 pgs) 0WP 0005 00 (1 pgs) 0

*Zero in this column indicates an original page.

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TECHNICAL BULLETIN

INSTALLATION AND FITTING INSTRUCTIONSFOR

M45 MASK THERMOPLASTIC LINER

REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS

You can help improve this manual. If you find any mistakes or if you know of a wayto improve the procedures, please let us know. Mail your letter, DA Form 2028(Recommended Changes to Publications and Blank Forms), or DA Form 2028-2located in the back of this manual direct to: Commander, USA SBCCOM,ATTN: AMSSB-RBD-B, 5183 Blackhawk Road, Aberdeen Proving Ground, MD21010-5424. A reply will be furnished to you.

DISTRIBUTION STATEMENT C : Distribution authorized to U.S. Government agencies and theircontractors to protect technical or operational information. This determination was made on1 September 1994. Other requests for this document will be referred to: Commander,USA SBCCOM, ATTN: AMSSB-RBD-B, 5183 Blackhawk Road, Aberdeen Proving Ground, MD21010-5424.

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TABLE OF CONTENTSWP Sequence No.

WARNING SUMMARY

General Information............................................................................................................... 0001 00Initial Sizing and Fitting.......................................................................................................... 0002 00Custom Sizing and Fitting...................................................................................................... 0003 00Maintenance Procedures....................................................................................................... 0004 00M45 Thermoplastic Liner Parts List....................................................................................... 0005 00

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GENERAL INFORMATION 0001 00

0001 00-1

M45 Mask Thermoplastic Liner

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GENERAL INFORMATION 0001 00

0001 00-2

DESCRIPTION

The Thermoplastic Liner (TPL) used with the M45 Mask consists of a Layer Assembly (1), CoverAssembly (2) and Brow Pad (3). It is cut smaller than the standard thermoplastic liner to allow room forthe M45 mask and hood. When the M45 mask is not worn, a brow pad included with the TPL fills thespace normally taken up by the mask.

OPERATION

Use the M45 thermoplastic liner only when you plan to wear the M45 mask. The brow pad is used in twosituations: while you are on a mission and have removed the M45 mask, and when you are going on amission without the M45 mask donned but you expect to don the mask during the mission. When you usethe M45 TPL, the helmet bag that you carry to the aircraft should contain either the M45 mask or the browpad; you should be wearing whichever item is not in the helmet bag. If you do not plan to use the M45mask, do not use the M45 thermoplastic liner or the brow pad; use the standard thermoplastic linerinstead.

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INITIAL SIZING AND FITTING 0002 00

0002 00-1

INITIAL SETUP

Maintenance Level

Unit

Materials/Parts

Helmet, Flyer's, HGU-56/P (Items 2-7, WP 0005)Mask, Chemical-Biological: M45 (Items 8-11, WP 0005)Thermoplastic Liner, M45 (Items 17-22, WP 0005)

Personnel Required

Operator wearing a properly sized and fitted M45 Mask and HGU-56/P HelmetAssembly with standard TPL

ALSE Specialist/Technician with ASI of H2/Q2 (ALSE Qualified)

PREPARING THE HELMET__________WARNING

Proper fitting of the helmet with the M45 thermoplastic liner is essential to the functioningof the HGU-56/P when used with the M45 Mask, all of its modules, and the safety of theoperator. Take as much time as necessary to install and fit the kit properly. Use extremecare in checking fit.

NOTE

If optical systems, Aviator's Night Vision Imaging System (ANVIS) or AH-1 are to be used, checkhelmet fit with optical systems attached.

During the fitting, the operator must wear a properly sized, fitted, and adjusted M45Mask. Have the operator don the mask before donning the helmet.

In preparation for the fitting procedure, operator's with long hair should arrange theirhair so that it lies flat and is completely covered by the helmet. Elevated hair styles such asbuns or French braids will prevent proper fitting of the helmet. The helmet must be worn thesame way thereafter.

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0002 00-2

PREPARING THE HELMET - Continued

1. Remove the standard thermoplastic liner from the helmet.2. Attach the flat side of the brow pad (1) to the hook fasteners at the front of the energy-absorbing liner

(2), ensuring that the bottom edge of the brow pad (3) is flush with the front edge of the energy-absorbing liner.

3. Install the M45 thermoplastic liner in the helmet, ensuring that:• the front edge of the thermoplastic liner is flush with the top edge of the brow pad,• the thermoplastic liner is against the crown of the helmet, the holes (4) in the front of the

thermoplastic liner align with the plenum ports (5)• the rear edge of thermoplastic liner is aligned with the top edge of the nape strap pad and sits

squarely in the helmet, and• the nape strap pad (6) is completely pulled down so that the keeper tab is taut.

4. Remove the brow pad from the helmet.

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0002 00-3

INITIAL FITTING OF THE HELMET

1. With the Mask donned, have the operator don the helmet as follows:a. Hook the thumbs in the earcups and spread the helmet slightly.b. Position the helmet firmly against the forehead; rotate the helmet rearward and down onto the

head.c. Press the helmet down firmly with both hands to ensure that the helmet is properly positioned on

the head.2. Align the helmet with the forehead reference point.3. Adjust the earcups so that they cover the operator’s ears. Check earseal compression and adjust as

necessary in accordance with TM 1-8415-216-12&P, paragraph 4-11.4. Fasten and adjust the chinstrap.5. Lower the visors to check centering and nose clearance. If necessary, adjust the visors as follows:

a. Loosen the downstop locking screws (one on each side of the visor) and adjust as necessary.b. When the desired visor position is attained, tighten the screws.

6. Adjust the nape strap pad for the closest fit possible.7. Check the fit of the pad with your index finger.8. Ask the operator to evaluate the fit. If the fit is

acceptable, skip to Step 12. If a pressure point exists,proceed to Step 9.

9. Have the operator remove the helmet. Add headbandfitting pads (1) to the energy-absorbing liner (2) where itcontacts the brow pad, two on either side of the pressurepoint to even the pressure.

10. Have the operator don the helmet again. If a pressurepoint remains, custom-fitting may be required. Refer tothe WP 0003 00.

NOTE

If the operator cannot be fitted in accordance with thefitting instructions, contact the United States ArmyAeromedical Research Laboratory (USAARL).

11. Repeat Steps 4-7 for a final fit check with the mask.

NOTE

Adjust ANVIS goggles as necessary for maximized field of view.

12. If optical systems (ANVIS goggles, AH-1 sight) are used, place the systems in normal operatingposition and check for full operational capability in accordance with TM 11-5855-263-10 for ANVISgoggles and TM 9-1270-212-14&P for the AH-1 sight.

13. Remove the helmet and the mask.14. Reinstall the brow pad. Ensure the bottom edge of the brow pad is flush with the edge of the energy

absorbing liner.15. Have the operator don the helmet without the mask. Repeat steps 4-9.16. After the first flight, recheck and adjust as necessary the helmet straps, the thermoplastic liner, and

the earcups.

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CUSTOM SIZING AND FITTING 0003 00

0003 00-1

INITIAL SETUP

Maintenance Level

Unit

Materials/Parts

Gloves (Item 1, WP 0005)Helmet, Flyer's, HGU-56/P (Items 2-6, WP 0005)Mask, Chemical-Biological: M45 (Items 8-11, WP 0005)Oven (Item 12, WP 0005)Oven Thermometer (Local purchase)Talcum Powder (Item 14, WP 0005)Tape, Pressure-Sensitive Adhesive (Item 15, WP 0005)Thermoplastic Liner, M45 (Items 17-22, WP 0005)Timer or equivalent (Local purchase)

Personnel Required

Operator wearing a properly sized and fitted M45 MaskALSE Specialist/Technician with ASI of H2/Q2 (ALSE Qualified)

__________WARNING

Proper fitting of the helmet with the M45 thermoplastic liner kit is essential to the functioning ofthe HGU-56/P when used with the M45 CB Protective Mask, all of its modules, and the safety ofthe operator. Take as much time as necessary to install and fit the kit properly. Use extremecare in checking fit.

CAUTION

If you are using a non-convection oven to heat the thermoplastic liner, ensure that the upperburner elements do not activate during heating, or plastic layers will melt.

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0003 00-2

PREPARING THE THERMOPLASTIC LINER

NOTE

Do not use a microwave oven; it will not heat the plastic layers.

1. Set the oven rack (1) to the lowest position (2); heat theoven to 200°F ± 5°F (93.3°C ± 2.8°C).

CAUTION

Before you place the thermoplastic liner in the oven,ensure that the cover is attached properly. If the cover isinstalled backward or not aligned properly, the layerscould become damaged during fitting, making the TPLunserviceable.

2. Place the thermoplastic liner in the center of the rack in theheated oven, cloth side on rack.

3. Ensure that the oven stabilizes at the temperature specified in Step 1 before you set the timer.4. Set the timer, stopwatch, or equivalent for 10 minutes. Heat the thermoplastic liner for approximately

10 minutes.5. While the thermoplastic liner heats, review HELMET CUSTOM FITTING, steps 1-5, so that they may

be completed in 30 seconds or less.6. Check the oven temperature with an over thermometer every three to five minutes during the heating

process. Adjust the oven controls if the temperature falls outside the range specified in Step 1.7. Describe the fitting procedure to the operator being fitted.

PREPARING THE HELMET AND MASK

If headband fitting pads are installed in the helmet, remove them.Attach the brow pad to the hook fasteners on the energy-absorbing liner, ensuring that the bottom edge ofthe brow pad is flush with the front edge of the liner.Cover the hook fastener on the nape strap pad with pressure-sensitive tape to ease installation of theheated thermoplastic liner.Loosen the nape strap pad.Sprinkle a light coat of talcum powder over the mask hood to ease donning of the hot TPL.

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0003 00-3

HELMET CUSTOM FITTING__________WARNING

Handle the heated thermoplastic liner carefully; the plastic layers will be hot. Touch the fabriccover only. Wear gloves if necessary.

NOTE

Steps 1-5 should be completed in 30 seconds or less.

1. Remove the thermoplastic liner from the oven.

CAUTION

Do not deform the hot, soft thermoplasticliner by pressing too hard in any one areawhen positioning the liner in the helmet.

2. Squeezing the sides of the thermoplastic liner(1) to clear the earcups (2), install the liner inthe helmet. Ensure that the label and holeson the liner are positioned toward the front ofthe helmet.

3. Have the operator hold the helmet upsidedown. Position the thermoplastic liner so thatthe front edge is flush with the top edge of thebrow pad. Ensure that the liner is centered inthe helmet.

4. Position the top of the thermoplastic liner inthe helmet. Position the rear of thethermoplastic liner against the top edge of,but not down on, the nape strap pad whileholding the nape strap pad keeper tab taut.

5. Remove the brow pad.

CAUTION

When donning or removing the helmet, spread the helmet just enough to clear the head.Excessive spreading may damage the helmet.

6. Have the operator hook his/her thumbs in the earcups and spread the helmet slightly. Place the frontof the helmet against the forehead reference point. Hold the edge of the thermoplastic liner and napestrap pad with your hand and pull down. Have the operator don the helmet and rotate the helmetrearward.

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0003 00-4

HELMET CUSTOM FITTING - Continued

7. Have the operator pull downward with his/her hands on top of the helmet until it is seated firmly onthe head. Lower the visor to check nose centering and clearance. Fasten the chinstrap and the napestrap and tighten them as much as possible without causing excessive discomfort. This will optimizethe operator’s peripheral vision. Have the operator maintain as much downward pressure aspossible, without causing excessive discomfort, for 3-5 minutes.

NOTE

The thermoplastic liner should be compressed as much as possible; this will afford a low center ofgravity and long-lasting comfort.

8. Release pressure on top of the head and removethe helmet. Ensure that the thermoplastic liner liessmoothly in the helmet.

NOTE

If the thermoplastic liner is not properly fitted,reheat the thermoplastic liner and repeat thefitting procedure.

9. Remove the pressure sensitive tape from the napestrap (1) pad hook fastener.

10. Have the operator don the helmet. Adjust theearcups; tighten the nape strap and the chinstrap.

11. Perform a final fit check. No pressure pointsshould exist; if they do, remove the thermoplasticliner from the fitting shell and repeat the fittingprocedure.

12. If the operator does not have a full field of view with the ANVIS, remove the thermoplastic liner fromthe helmet and reheat it. Reinstall the thermoplastic liner in the helmet, have the operator don thehelmet, and press the front of the helmet against the head to compress the thermoplastic liner asmuch as possible.

13. If the fit is still too tight after the thermoplastic liner has been custom-fitted, select the next largerhelmet size.

14. If the helmet fits properly, perform Steps 2-6 of HELMET CUSTOM FITTING for a final fit check.

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MAINTENANCE PROCEDURES 0004 00

0004 00-1

CLEANING

COMPONENT CONDITION PROCEDURE

Brow Pad Dirt, Stains, Grease

Hand wash, cool orlukewarm water, mildliquid detergent, airdry only

Cover Assembly Dirt, Stains, Grease

Hand or machine(gentle cycle) wash,cool or lukewarmwater, mild detergent,air dry

Layer Assembly DirtWipe clean withdamp cloth. Replace2-sided tape

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0004 00-2

REPLACING BROW PAD

INITIAL SETUP

Maintenance Level

Unit

Materials/Parts

Brow Pad

Personnel


1. Remove the brow pad (1) from the helmet (2).2. Attach the flat side of the replacement brow pad to the hook fasteners at the front of the energy-

absorbing liner (3), ensuring that the bottom edge of the brow pad (4) is flush with the front edge ofthe energy-absorbing liner.

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0004 00-3

REPLACING COVER ASSEMBLY

INITIAL SETUP

Maintenance Level

Unit

Materials/Parts

Cover AssemblyTape PSA Double Sided (Item 16, WP 0005)Shears, Bent Trimmers (Item 13, WP 0005)

Personnel


1. Squeeze the sides of the thermoplastic liner to clear the earcups, and remove the TPL from thehelmet (See WP 0003, HELMET CUSTOM FITTING, Step 2).

2. Remove the thermoplastic liner cloth cover (1) as follows:3. Remove and discard the thread (2)

attaching the cover to the plastic layers(3). Replacement of the thread is notnecessary.

4. Fold the sides of the cover down toexpose the double-sided tape (4).

5. Remove the cover from the layers.6. Remove the double-sided tape from the

layer assembly.7. Cut two 2-1/2-inch pieces of double-

sided tape.8. Attach a piece of double-sided tape to

each side of the layer assembly (wherethe old tape was removed).

9. Turn the replacement cloth cover insideout. Place the cover inside the layerassembly. Fold the sides of the clothcover over the layer assembly. Ensurethat the cover is positioned properly.

10. Reinstall the TPL in the helmet (See WP 0003, HELMET CUSTOM FITTING, Step 2). Align the rearedge of the liner with the top edge of the nape strap pad; align the front edge of the liner with the topedge of the brow pad. Ensure that the nape hanger strap is taut and that the hook-and-pile fastenersare engaged.

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M45 THERMOPLASTIC LINER PARTS LIST 0005 00

0005 00-1

ITEM NOMENCLATURE PART NUMBER NATIONAL STOCKNUMBER

1 Gloves, Men’s J729 8415-01-189-6387

2 Helmet, Flyer’s, HGU-56/P(Extra Large) 1680-ALSE-101-1 8415-01-394-8032

3 Helmet, Flyer’s, HGU-56/P(Large) 1680-ALSE-101-2 8415-01-394-8033

4 Helmet, Flyer’s, HGU-56/P(Medium) 1680-ALSE-101-3 8415-01-394-8036

5 Helmet, Flyer’s, HGU-56/P(Small) 1680-ALSE-101-4 8415-01-394-8034

6 Helmet, Flyer’s, HGU-56/P(Extra Small) 1680-ALSE-101-5 8415-01-394-8035

7 Helmet, Flyer’s, HGU-56/P(Extra-Extra Small) 1680-ALSE-101-6 8415-01-394-6474

8 Mask, Chemical-Biological;M45 (Extra Small) 5-1-2800-10 4240-01-414-4034

9 Mask, Chemical-Biological;M45 (Small) 5-1-2800-20 4240-01-414-4035

10 Mask, Chemical-Biological;M45 (Medium) 5-1-2800-30 4240-01-414-4051

11 Mask, Chemical-Biological;M45 (Large) 5-1-2800-40 4240-01-414-4052

12 Oven, Baking and Roasting,Portable T4800 7310-01-364-4043

13 Shears, Bent Trimmers GGG-S-00278 5110-00-162-2203

14 Talcum Powder U-T-30 8510-00-817-0295

15 Tape, Pressure SensitiveAdhesive UU-T-93 7510-00-198-5831

16 Tape PSA Double Sided 750-01-317-8459

17 Thermoplastic Liner, M45(Extra-Extra Small) 5-1-2873-10 4240-01-455-7982

18 Thermoplastic Liner, M45(Extra Small) 5-1-2873-20 4240-01-456-4510

19 Thermoplastic Liner, M45(Small) 5-1-2873-30 4240-01-456-4509

20 Thermoplastic Liner, M45(Medium) 5-1-2873-40 4240-01-456-4512

21 Thermoplastic Liner, M45(Large) 5-1-2873-50 4240-01-456-4511

22 Thermoplastic Liner, M45(Extra Large) 5-1-2873-60 4240-01-456-4516

By Order of the Secretary of the Army:

ERIC K. SHINSEKIGeneral, United States Army

Chief of StaffOfficial:

JOEL B. HUDSONAdministrative Assistant to the

Secretary of the Army9921101

PIN: 077437-000

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