OPERATOR MAINTENANCE INSTRUCTIONS
M50/M51 Common Items
10 Before Chin Cup and Beard
Visually inspect chin cup and beard for tears, holes, and signs of deterioration or other damage.
Chin cup or beard is torn, has holes or other damage and/or shows signs of deterioration. Report to next higher level of maintenance.
11 Before Nosecup
Nosecup Facepiece Assembly Not Shown For Clarity
Front Rear
Internal Drink Tube Alignment Arrow
Gently pull back chin cup and visually inspect nosecup for tears, holes, signs of
deterioration or other damage.
Ensure internal drink tube alignment arrow is visible.
Nosecup is torn, has holes or other damage and/or shows signs of deterioration. Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
12 Before Inlet/Outlet Disk Valves, Left and Right
Right Nosecup and Head Harness
Not Shown For Clarity a. Gently pull back nosecup and
pull air deflector away from filter mount clamp ring, left or right to expose inlet/outlet disk valve.
Inspect the air deflectors for damage or deterioration. Remove inlet/outlet disk valve (WP 0030 00) and visually inspect for damage and/or deterioration.
Air deflectors are damaged or show signs of deterioration.
Inlet/outlet disk valve is damaged and/or shows signs of deterioration.
Report to next higher level of maintenance.
b. Inspect valve seat and valve mounting post for damage.
Valve seat is damaged and/or valve mounting post is broken. Report to next higher level of maintenance.
c. Reinstall inlet/outlet disk valves and air deflectors. Ensure air deflectors mount snugly over filter mount clamp rings, left and right.
Air deflectors will not mount snugly over filter mount clamp rings, left and right. Report to next higher level of
maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
13 Before Internal Drink Tube Nosecup and Head Harness
Not Shown For Clarity
Internal Drink Tube
a. Visually inspect internal drink tube for damage, and signs of deterioration.
Internal drink tube is damaged or shows signs of deterioration. Report to next higher level of maintenance.
b. Ensure internal drink tube moves from stowed position to drink position by rotating the drink tube lever on the front module main body upward.
Drink tube does not move. Report to next higher level of maintenance.
a. Inspect outsert lens for cracks, chips, or discoloration that affects vision. Inspect outsert locking tabs for breaks or cracks.
Outsert is broken, distorted, or discolored enough to impair vision.
Outsert locking tabs are broke or cracked. Report to next higher level of maintenance.
b. Inspect Outsert Pouch for tears, rips or other damage.
The Outsert Pouch is torn, ripped, or otherwise unserviceable. Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF: a. Inspect water canteen cap for
dirt, damage and tight
connection with drink coupler.
Water canteen cap is damaged or does not make tight connection with drink coupler.
Report to next higher level of maintenance.
b. Inspect water canteen cap for missing, damaged, or
deteriorating drink coupler “O”
ring and internal canteen seal.
“O” ring or canteen seal are missing, damaged, or show signs of deterioration. Report to next higher level of maintenance.
c. Inspect water canteen cap retaining strap for damage and deterioration.
Water canteen cap retaining strap is
damaged or shows signs of deterioration.
Report to next higher level of maintenance.
d. Ensure canteen cap fits on canteen.
Canteen cap will not fit on canteen. Report to next higher level of maintenance.
16 Before Mask Function a. Don the M50 (WP 0005 00-13) or M51 (WP 0005 00-20) mask with M61 filters. Check the mask for leaks.
Mask fails to seal.
Report to next higher level of maintenance.
b. Check to see that you are able to drink while wearing the mask (WP 0005 00-1, -3, -4).
Unable to drink while wearing the mask.
Report to next higher level of maintenance.
c. Check to see that you can see through the eyelens and outsert.
Unable to see through the eyelens or outsert.
Report to next higher level of maintenance.
d. Check for excessive breathing resistance.
There is excessive breathing resistance.
Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
17 Before Waterproofing Bag
Waterproofing Bag
Resealable Bag
a. Inspect waterproofing bag for cracks, tears, holes, and/or brittleness.
Waterproofing bag is torn, has holes, or is brittle. Report to next higher level of maintenance.
b. Check that three rubber bands are in bag and are not sticky, broken, or brittle.
Rubber bands are missing or are sticky, broken, or brittle. Report to next higher level of maintenance.
18 Before Operator Cards
a. Ensure operator cards are present.
Operator cards are missing. Report to next higher level of
maintenance.
b. Inspect operator cards for faded or discolored text and graphics making them difficult to read.
Operator cards are faded, discolored, or otherwise difficult to read. Report to next higher level of maintenance.
c. Inspect operator cards binding for damage preventing cards from being turned or bound together.
Binding is damaged preventing cards from being turned or bound together. Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
M51 Specific Items
19 Before Hose a. Inspect hose assembly for splits, cracks, or breaks.
Hose is split, cracked or broken. Report to next higher level of
maintenance.
b. Check hose connectors for damage or dirt. Rotate hose filter connector to make sure it will swivel freely.
Hose connectors are damaged or dirty. Filter hose connector will not swivel freely. Report to next higher level of maintenance.
c. Check to see that you are able to connect to the vehicle collective protection system. Check hose attachment and clothing clip.
Unable to connect to the vehicle collective protection system.
Report to next higher level of maintenance.
20 Before Microphone and
a. Remove microphone and microphone adapter from mask (WP 0012 00).
b. Inspect microphone and adapter for damage or corrosion to two and three pin connectors and connector receptacles. Check for missing or damaged retaining screws.
Microphone or microphone adapter are damaged or show signs of corrosion.
Report to next higher level of maintenance.
c. Visually inspect microphone adapter gasket for damage and deterioration.
Gasket is missing, damaged, or shows signs of deterioration.
Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
d. Ensure that microphone and microphone adapter can be securely installed in the
communications port inside the mask (WP 0012 00).
Microphone and adapter cannot be securely installed in communications port.
Report to next higher level of maintenance.
e. Check microphone and microphone adapter for proper operation by connecting to the helmet and activating vehicle communications system (WP 0012 00).
Unable to
communicate through the microphone and adapter. Report to next higher level of maintenance.
21 Before Communications
Lead Communications
Lead
Check lead for breaks, cuts, corrosion, abrasions, and damage to connectors.
Lead and/or connector are damaged or show signs of corrosion.
Report to next higher level of maintenance.
22 Before Protective Hood
Protective Hood a. Inspect protective hood for
cuts, holes, or tears using an adequate light source.
Protective hood has cuts, holes, or tears.
Report to next higher level of maintenance.
b. Check pivoting buckle and filter mount elasticized straps for breaks fraying, tears or rips
Elasticized straps are broken, frayed or otherwise damaged.
Report to next higher level of maintenance.
c. Check hood for proper size Incorrect size, Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
23 Before Mask carrier extension strap
Mask Carrier Extension Strap Visually inspect mask carrier
extension strap for fraying, tears or rips and damaged or missing hardware.
Mask carrier extension strap is severely frayed, torn, or ripped or attaching hardware is damaged or missing.
Report to next higher level of maintenance.
Before Common AAL
a. Visually inspect vision correction support frame and vision correction Spec frame assembly for damage.
Ensure cam lock is present. Check vision correction lenses for
scratches/damage.
Vision correction support frame and/or vision correction spec frame assembly are damaged preventing their use. Cam lock is missing. Vision correction lenses are scratched or damaged.
Report to next higher level of maintenance b. Inspect facepiece assembly to
ensure mounting frame support stand-off is present
Vision correction support frame stand-off is missing or damaged.
Report to next higher level of maintenance
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
(if issued) Audio Frequency Amplifier
Audio Frequency Amplifier Adapter
a. Visually inspect the audio frequency amplifier for damage or corrosion to top and bottom locking clamps, top locking clamp prongs, on-off switch, battery compartment, battery compartment cover and screw and two-pin connector to communications port receptacle.
Top and bottom locking clamps, top locking clamp prongs, on-off switch, battery compartment, battery compartment cover and screw or two-pin connector to
communications port receptacle are damaged or show signs of corrosion.
Report to next higher level of maintenance.
b. Visually inspect two and three-pin connectors on audio frequency amplifier adapter for damage or corrosion.
Two or three –pin connector on audio frequency amplifier adapter is bent, broken, or shows signs of corrosion. Report to next higher level of maintenance.
c. Visually inspect amplifier adapter gasket for damage and
deterioration.
Gasket is missing, damaged, or shows signs of deterioration.
Report to next higher level of maintenance.
26 Before ATC
Microphone, (5 Ohm) (if issued)
ATC 5 Ohm Microphone, M101
Retaining Screws
Visually inspect two-pin connector receptacle on microphone for damage, corrosion and missing retaining screws.
Two-pin connector receptacle on microphone is
damaged, shows signs of corrosion or retaining screws are missing.
Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
27 Before ATC
Microphone, (150 Ohm) (if issued)
ATC 150 Ohm Microphone, P/N 938-2900 Retaining
Screws
Visually inspect two-pin connector receptacles on microphones for damage, corrosion and missing retaining screws.
Two-pin connector receptacle on microphone is
damaged, shows signs of corrosion or retaining screws are missing.
Report to next higher level of maintenance.
28 Before Special cable assembly,
(if issued)
Cable Assembly, Special NSN: 5995-01-502-5501 Visually inspect cable assembly
connectors to communications port in front module main body, to push-to- talk and to ATC system
equipment for damage and corrosion.
Cable assembly is broken and/or connectors are
damaged or show signs of corrosion. Report to next higher level of maintenance. Visually inspect cable assembly
connectors to communications port in front module main body, to push-to- talk and to ATC system
equipment for damage and corrosion.
Cable assembly is broken and/or connectors are
damaged or show signs of corrosion. Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
30 Before Microphone Cable
Microphone Cable NSN: 5965-01-443-5490
Visually inspect microphone cable connectors to communications port in front module main body, to push-to- talk and to ATC system
equipment for damage and corrosion.
Microphone cable is broken and/or connectors are
damaged or show signs of corrosion. Report to next higher level of maintenance.
31 Before Microphone adapter
(if issued)
Microphone Adapter
Adapter Gasket
a. Visually inspect two and three pin connectors on microphone adapter for damage or corrosion.
Two or three pin connector on
microphone adapter is bent, broken, or show signs of corrosion.
Report to next higher level of maintenance.
b. Visually inspect microphone adapter gasket for damage and deterioration.
Gasket is missing, damaged, or shows signs of deterioration.
Report to next higher level of maintenance.
32 Before Laser Outsert Assembly
a. Inspect outsert lens for cracks, chips, or discoloration that affects vision. Inspect outsert locking tabs for breaks or cracks.
Outsert is broken, distorted, or discolored enough to impair vision.
Outsert locking tabs are broke or cracked.
Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
b. Inspect Outsert Pouch for tears, rips or other damage.
The Outsert Pouch is torn, ripped, or otherwise
unserviceable. Report to next higher level of maintenance.
33 Before Sunlight Outsert
a. Inspect outsert lens for cracks, chips, or discoloration that affects vision. Inspect outsert locking tabs for breaks or cracks.
Outsert is broken, distorted, or discolored enough to impair vision.
Outsert locking tabs are broke or cracked.
Report to next higher level of maintenance.
b. Inspect Outsert Pouch for tears, rips or other damage.
The Outsert Pouch is torn, ripped, or otherwise
unserviceable. Report to next higher level of maintenance.
34 Before Mask carrier extension
strap
Mask Carrier Extension Strap Visually inspect strap for fraying,
tears or rips and damaged or missing hardware.
Extension strap is severely frayed, torn, or ripped or attaching hardware is damaged or missing. Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
35 Before Decontaminati on Kit M291
Visually inspect to ensure these items are present and mission capable as required by individual service directive. NOTE: Only the NAAK or the ATNNA and the Decontamination Kit, M291 or the RSDL need to be present.
All items are not present as required by individual service equipment directive.
1 During Mask Seal If wearing the mask for an
extended period of time, check the mask seal every 4 hours using negative pressure test (WP 0005-15) to ensure seal has not been broken.
Seal has been broken.
Table 1. Operator Preventive Maintenance Checks and Services – Continued ITEM
NO. INTERVAL
ITEM TO BE CHECKED OR
SERVICED
PROCEDURE NOT FULLY MISSION CAPABLE IF:
After
WARNING
If you have not used your mask for 30 days or more, perform all PMCS prior to using your mask.
WARNING
DO NOT use tissue paper or a paper towel to remove dirt or moisture from front module cover, outlet disk valve, or outlet valve seat. Paper may break up and lodge in outlet disk valve area causing leakage.
CAUTION
DO NOT use high-pressure water to clean mask; it may damage components.
CAUTION
Mask must be clean prior to conducting PMCS and cleaned after operations. Sanitizing will be conducted prior to re-issue to another warfighter or prior to turn-in as excess.
NOTE
If components identified in PMCS are not present, notify next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
a. Visually inspect carrier for fraying, tears or rips and damage to hook and pile fasteners.
Severely frayed, torn, or ripped or there is damage to the hook and pile fasteners.
Report to next higher level of maintenance.
b. Visually inspect carrier waist strap, leg strap, and MOLLE attachment panel for fraying, tears or rips and damaged or missing hardware.
Waist strap, leg strap or MOLLE attachment panel are severely frayed, torn, or ripped or attaching hardware is damaged or missing.
Report to next higher level of maintenance.
c. Check for mildew, solvents, or abrasive materials that might harm mask assembly. Check seams for broken stitches.
Mildew, solvents, or abrasive materials are present. Seams are broken or stitching is loose. Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
2 After Individual
Equipment Carrier Bag
Individual Equipment Carrier Bag Inside View
a. Visually inspect bag for fraying, tears or rips. Inspect slide fastener and snaps for damage.
Severely frayed, torn, or ripped. Slide fastener or snaps damaged.
Report to next higher level of maintenance.
b. Visually inspect AAL item hold-down straps in interior of bag for fraying, tears or rips. Ensure hold-down straps are secured to bag.
Severely frayed, torn, or ripped or not secured to bag. Report to next higher level of maintenance.
c. Check for mildew, solvents, or abrasive materials that might harm AAL items. Check seams for broken stitches.
Mildew, solvents, or abrasive materials are present. Seams are broken or stitching is loose. Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
3 After Facepiece
Assembly
a. Remove clear outsert from mask, if attached.
b. Inspect facepiece assembly for holes, tears, and splits. Look closely at edges of mask assembly.
Inspect for soft or sticky spots.
Inspect for stiff areas that crumble when rubbed between fingers and for cracks that expand when rubber is stretched.
There are tears or holes in the facepiece.
Facepiece has soft or sticky spots that allow air to enter mask assembly or stiff areas that crumble when rubbed between fingers and cracks that expand when rubber is
stretched. Report to next higher level of maintenance.
c. Visually inspect eyelens for cracks, cuts, scratches, or stains that affect vision.
The eyelens is cracked or is scratched so as to impair vision. Report to next higher level of maintenance.
d. Pull head harness brow strap slots, head harness buckles and facepiece beard and visually inspect for rubber deterioration.
There are signs of rubber deterioration Report to next higher level of maintenance.
e. Visually inspect bonding around the eyelens.
Bonding around
eyelens is not secure or appears to be coming loose. Report to next higher level of maintenance.
f. Visually inspect head harness pivoting and ladder lock buckles for damage.
Buckles are broken or missing. Report to next higher level of
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
g. Visually inspect facepiece interior and ensure vision correction stand-off is present.
Vision correction stand-off missing or damaged 4 After Head Harness
a. Visually inspect skullcap and stitching, head harness straps and brow strap covers.
Skullcap is cut, ripped, or torn; stitching is loose or coming apart;
brow strap covers are damaged. Report to next higher level of maintenance.
b. Inspect head harness for loss of elasticity.
Head harness will not hold mask assembly firmly against face.
Report to next higher level of maintenance.
c. Pull on head harness straps and make sure buckles hold straps tight.
Buckles will not hold straps. Report to next higher level of
maintenance.
5 After Outlet Valve Cover
Assembly
Outlet Valve Cover Assembly Facepiece Assembly Not Shown For Clarity
Rear
a. Remove outlet valve cover assembly, (WP 0025 00) and visually inspect for breaks or other damage.
Cover is broken, cracked or otherwise damaged. Report to next higher level of maintenance.
Table 1. Operator Preventive Maintenance Checks and Services – Continued
PROCEDURE NOT FULLY MISSION CAPABLE IF:
b. Inspect communications port cover for damage and ensure front cover baffle is in place and secure.
b. Inspect communications port cover for damage and ensure front cover baffle is in place and secure.