MSA LH 050 User manual

Maintenance manual
PP020210-01
MAINTENANCE MANUAL
FLIGHT HELMET LH 050

Maintenance manual
MSA, Châtillon sur Chalaronne • Tél. [phone] •
E-mail [e-mail]
1
Table of Contents
Page
Table of Contents 1/22
- Warning notice 2/22
- Helmet description 3/22
- Warranty 3/22
- Introduction 4/22
1 – Chinstrap 5/22
2 – Inner liner elements 6/22
3 – Edge roll 7/22
4 – Inner visor 8/22
5 – Audio cable 9/22
6 – Microphone unit and cover (standard or winchman's) 10/22
7 – Mixed microphone boom 11/22
8 – Microphone boom 12/22
9 – Removing the complete microphone 13/22
10 – Earphones and hygiene parts of the ear cups 14/22
Servicing and maintenance table 15/22
Inspection table and replacement criteria 16/22
Appendices: Replacement criteria 17 to 22/22

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WARNING NOTICE
Thank you for putting your trust in
MSA
products.
Read these instructions carefully before using your helmet.
Failure to follow these instructions could reduce the level of protection provided
by your helmet.
The level of protection provided by the helmet is only guaranteed if it has all the
original MSA parts. Therefore, any modifications made to your helmet or the absence of
any of the parts forming the original helmet will make the equipment supplied non-compliant,
releasing MSA from all liability.
In order to keep improving its products, MSA reserves the right to modify them
without prior notice.
To provide sufficient protection, this helmet must be fitted and adjusted to the head size
of its wearer.
The helmet is made in such a way that any energy received during an impact is absorbed
by the destruction of or partial damage to the shell and impact cap; even if this damage is not
immediately apparent, replacement of the whole helmet is recommended after a major
impact.
Users' attention is also drawn to the danger of modifying or removing any of the original
parts of the helmet except where the modification or removal is recommended by the helmet
manufacturer. Under no circumstances should helmets be adapted so that accessories can
be attached using a process not recommended by the helmet manufacturer.
Do not apply paints, solvents, adhesives or stickers, except those recommended by the
helmet manufacturer's instructions.
The MSA
LH 050 flight helmet is designed solely for helicopter pilots and helicopter
flight crew. It provides maximum comfort and protection.
It is available in three sizes, covering head circumferences from 52 cm to 64 cm. It
has an integrated visor and can be fitted with a wide range of communication systems,
on request. Contact us for more details.
Traceability is assured by a label showing a serial number.
After any obvious impact an inspection should be carried out by the maintenance
department or specialist workshop .

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FLIGHT HELMET LH 050
HELMET DESCRIPTION
Description:
•The shell of the helmet consists of:
-an outer shell made from high performance composites,
-an expanded polystyrene impact cap to absorb shocks, covered with an
inner liner.
•The inner liner consists of a T-shaped comfort liner and a neck pad.
The helmet is adapted to the shape of the wearer's head by personalising the
T-shaped comfort liner and the neck pad and the adjustment pads for adjusting the
pressure of the ear cups on the ears.
•The helmet has 1 inner protective visor.
•The ear protection system consists of:
-two ear cups, containing a housing for installing the earphones.
-two ergonomic comfort ear seals.
The ear cups provide excellent ear protection and are fixed inside the shell by means
of hook and loop pads.
•The helmet chinstrap is adjustable and fully removable.
•Every helmet is supplied with a protective bag and a personalisation kit.
•The helmet can accommodate a wide range of communication systems,
on request.
WARRANTY
All models, accessories and spares are subject to stringent checks before leaving
the factory.
MSA helmets and accessories are guaranteed for 12 months, parts and labour, from the
date of delivery to the buyer, against any failure during use under the conditions
described in this manual.
You also have a statutory warranty against hidden faults and defects subject to the
conditions laid down in Articles 1641 ff. of the French Civil Code.

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INTRODUCTION
Important: whenever you are handling the helmet, make sure you put it down on its
carry bag.
Tools required:
- 7 mm flat spanner
- 2 mm hexagonal screwdriver
-Flat screwdriver
-Philips screwdriver

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1. Chinstrap:
Tools: Philips screwdriver.
Dismantling duration: 15 seconds.
Mounting duration: 30 seconds.
The chinstrap is secured to the helmet by means of two screws on the left chinstrap
bracket.
To remove the chinstrap, unscrew the screws on the left side, then take out the
chinstrap levers by holding them by the ends.
To reinstall, engage each lever, making sure the chin cup is the right way round (the
return part of the strap should be uppermost) and so are the levers. Lock by pressing in
the middle of the lever. Tighten the 2 screws. You do not have to remove the chinstrap in
order to take off the chin cup.
Important: when reinstalling, the screws should be tightened 1/8 of a turn from when
the tightening stress increases (screwing into plastic).
Screws securing
the chinstrap

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2. Inner liner elements:
Tools: None.
Dismantling duration: 20 seconds.
Mounting duration: 45 seconds.
There are three inner liner elements:
The comfort liner with its interchangeable foam pieces, each supplied in 3 thicknesses
(4, 8 and 12 mm thick),
The neck pad (XS, S and M or L, XL and XXL depending on the helmet size),
The ear cups and their adjustment pads (3 on each side + 2 extra on each side),
The comfort liner is adjustable in 4 areas with 3 possible thicknesses (N.B. When
replacing the foam pieces, check that they are seated correctly). The neck pad is also
supplied in 3 different thicknesses. The liner elements are fixed to the impact cap and
shell with hook and loop tape, so no tools are needed.
N.B. Be careful not to break the polystyrene core of the neck pad during removal or
reinstallation. The audio cables must run between the edge roll and the neck pad (see
audio cable section).

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3. Edge roll
Tools: None.
Dismantling duration: 20 seconds.
Mounting duration: 45 seconds.
The edge roll is replaceable. It is attached to the rim by means of press studs
(3 on each side) and adjusts to fit the shell by means of two fastening pins. No tools are
needed for its removal and reinstallation.
When removing the edge roll, it is best to take out the ear cups and the neck pad first.
Then detach the 6 press studs and remove the 2 pins. When removing the first pin, it is
important to twist the edge roll then slide the pin along its slot. The second pin will then
come out easily on its own.
To reinstall the edge roll, engage the pins one after the other in the slots,
then fasten the press studs.

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4. Inner visor:
Tools: None.
Removal time: 15 seconds.
Reinstallation time: 30 seconds.
The inner visor is attached to its rotation system by means of clips.
Move the visor to the lowered position. Important: the direction of removal
of the inner visor is perpendicular to the 2 rivets of the visor attachments.
To reinstall it, check that the control levers of the inner visor are in the
lowered position.
Engage the visor so that the clips will go into their housings correctly.
Clip in by pressing on the ends of the visor.
Removal:
Pull the visor at a right angle
to the 2 rivets
R
einstallation:
Insert the clips into their housings
and push to clip the visor in place
Rotation system in
lowered position

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5. Audio cable:
Tools: Philips screwdriver.
Dismantling duration: 5 minutes.
Mounting duration: 5 minutes.
For this operation it is first necessary to remove the edge roll in order to access
the cable protection system.
- Remove the right ear cup,
- Remove the left ear cup,
- Remove the neck pad (make sure you do not break the piece of polystyrene inside
it),
- Put the ear cups inside the helmet,
- Remove the edge roll (see section 4),
- Unfasten the cable bushing from the connection circuit.
Unscrew the 2 screws of the cable protector and remove it
Carefully unplug the link cable to the Lz/Hz microphone switching box.
For reassembly, perform the same operations in reverse.
Warning: connect the JST plug on the link cable to the switching box on the circuit, in the
socket labelled "MIKE".

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6. Microphone unit and cover (standard or winchman's):
Tools: None.
Dismantling duration: 15 seconds.
Mounting duration: 30 seconds.
To remove the standard microphone cover (foam and attachment ring):
- Pull off the plastic ring (for the winchman's cover, pull off the cover itself).
- Remove the protective foam from the unit.
- Then pull off the microphone unit to separate it from its base.
To reinstall it, engage the unit in its mount, making sure the foolproofing notches are
the correct way round. Put on the cover followed by the ring, making sure the cutout for
the microphone arm and the 2 projections for attachment to the unit are
in the right place.
Cut out for microphone arm
Projections

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7. Combined microphone boom:
Tools: Philips screwdriver.
Dismantling duration: 1 minute.
Mounting duration: 1.5 minutes.
The left ear cup needs to be removed and the 3 press studs on the left side of the edge
roll should be undone.
Unplug the microphone's JST connector.
Remove the grommet from the shell.
Unscrew the central screw from
the microphone boom.
Unscrew the microphone boom,
making sure its components
remain stacked in the correct order.
For reassembly, perform the same operations in reverse.
Front of helmet
JST connector linked to connection circuitJST connector for
connecting microphone

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8. Microphone boom:
Tool: Philips screwdriver
Dismantling duration: 1 minute.
Mounting duration: 1 minute.
Inside the helmet, remove the left ear cup.
For reassembly, perform the same operations in reverse.
Perform the operations described
in section 10 up to the flat
metal washer.
Unscrew the
Philips screw
Remove the anti-rotation
washer
Inside the helmet
Outside the helmet

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9. Removing the complete microphone:
Tool: None
Dismantling duration: 2 minutes.
Mounting duration: 2 minutes.
Remove the grommet from the shell
(push it out from inside)
Outside
Inside
Inside the helmet, remove the left earphone.
Remove the inner liner by pulling the hook
and loop tape tab.
Disconnect the 2
JST connectors
From the outside of the helmet,
pull out the microphone cable.

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10.Earphones and hygiene parts of the ear cups:
Tools: 5.5 mm (box or flat) spanner
Dismantling duration: 3 minutes.
Mounting duration: 4 minutes.
To remove the earphones, take out the ear cups.
For each ear cup:
Remove the fabric seal.
Remove the 2 acoustic foam pieces
Pull the earphone cable away for easier access.
Unscrew the 2 nuts from the terminals.
(Keep the nuts, etc.)
Remove the 3 connectors.
To reassemble, proceed in the reverse order.

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GENERAL INFORMATION
This section concerns the tests and inspections required to determine the condition of
any units withdrawn from service.Dispose of any defective parts. All defective parts
should be disposed of and replaced with new parts from MSA only.
All tests should be carried out on clean parts (see section on cleaning).
Inspection, testing and maintenance table:
Basic checks*
Pre
-
flight
Visor cleanliness and operation yes
Presence and secure attachment of comfort elements (comfort liner,
neck pad, edge roll) yes
Condition of chinstrap and attachment points, operation of buckle
Operation of the chinstrap lever and condition of the strap yes
Communication system test yes
General condition of helmet yes
Shell (no cracks, no dents, aramid and carbon not visible, screws and
inserts in their housings) yes
Periodic checks*
frequency
Shell condition: particularly adhesion of chinstrap mounts, slight
impacts due to normal use 3 months
Condition of impact cap and rim: in particular adhesion of impact
cap to rim 3 months
Attachment of impact cap to shell 3 months
Inner visor condition and operation 3 months
Inner visor attachment 3 months
Condition of inner liner elements and ear cups 3 months
Operation of communication system (with inspection of cable condition) 3 months
Operation of chinstrap locking system 3 months
Condition of chinstrap and fastening buckle 3 months
Condition of the chinstrap strap 3 months
Check that all screws are tight 3 months
Check the play of moving sub-assemblies during operation 3 months
Condition of comfort liner pads 3 months
Cleaning (in accordance with the instructions given in the user manual) 3 months
Reco
mmended replacement of main parts*
frequency
Inner visor 5 years
Edge roll 2 years
Comfort liner and neck pad 2 years
Chinstrap attachment assembly 2 years
Chinstrap 2 years
Comfort ear seals 2 years
LH 050 chinstrap assembly 2 years
Impact cap 15 years
Shell 15 years
*: based on normal use of 200 hours per year and depending on the condition of
the part.

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MANDATORY INSPECTIONS AND REPLACEMENT CRITERIA
This section explains the mandatory action to be taken and the inspections necessary
when a helmet has suffered an impact OR when maintenance reveals damage caused
by an impact.
The mandatory action and necessary inspections are explained in the table below.
ACTION TO BE TAKEN
Condition
Impact:
The helmet shell is designed to protect against a
single impact
.
•The integrity of the shell is considered to have been
compromised after an impact.
•The shell of a helmet that has suffered an impact must
be destroyed and replaced.
IMPACT
CONFIRMED
Mandatory inspection
Suspected
impact:
Where damage caused by the impact is found. The helmet
must be inspected to check for
•Dents, cracking or deformation of the composite fibres
in the shell;
•Damage to the composite shell consisting of composite
fibres that have been cut or shredded;
•Removal of the outer coating leading to damage to the
gel coat layer and exposure of the composite fibres;
•Movement of the impact cap;
•Damage to the visors and the visor movement mechanisms;
•Damage to the chinstraps at the chinstrap anchor points and
the fastening buckle;
•The inspection must be recorded on the equipment
monitoring sheet.
If the inspection confirms an impact, the shell and the impact
cap must be replaced.
Mandatory
inspections if
an impact is
suspected
User and maintenance workshop
All helmet users and maintenance units are responsible for reporting known
or suspected impacts and damage to helmets.
MSA will not be held responsible for failure to remove from service a shell that
has been damaged or has suffered an impact.
Only MSA distributor is authorized to remove the impact cap. In case of doubt
about the integrity of the impact cap or the shell, contact your MSA distributor.

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APPENDICES: Replacement criteria
-LH 050 PM and GM shell and fittings
Sub
-
elements
-
Defects
Criteria
-
Ac
tion
Shell
Cracks and/or
scratches
Aramid fibres damaged*
Replace
Aramid fibres
not damaged* Nothing to report
Impacts Height of fall > 1 m
Replace
Height of fall < 1 m Nothing to report
Rail
Riveting Defective Replace
Attachment Coming apart Replace
Breakage Defective Replace
Wear Defective Replace
Chinstrap mount
Riveting Defective Replace
Attachment Coming apart Replace
Breakage Defective Replace
Wear Defective Replace
Edge seals Attachment Coming apart Rebond with glue

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Cosmetic defects (paint scratches, etc.)
do not require replacement of the shell.
Paint scratch
Scratch to paint and gel coat but no damage to aramid
or carbon.
Defect where the aramid and/or carbon are showing
The appearance of aramid and/or carbon filaments means
Deep scratch affecting the aramid (yellow) or carbon (black) in the
shell.
Hole following an impact revealing the aramid (yellow) or carbon (black) in the
shell.

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Warning
: cracked paint can signal an impact or that the shell
has been tightly squeezed; in this case the impact cap must be
removed to check the condition of the aramid inside the shell.
Impacts
If a helmet has one or more traces of impacts on the outside, the shell
must be replaced.
Specific traces of an impact inside the shell: concentric white lines matching the
cracks on the outside.
The appearance of carbon filaments in the area where the visor mechanism is
located means that the shell must be replaced.
Carbon fibre
Resin
Gelcoat
Paint
Cracks with or without replacement of the shell
If a helmet has one or more paint cracks on the outside and white marks
(delamination of the aramid) on the inside, the shell must be replaced.