Gentex HGU-56/P Troubleshooting guide

Operation and Maintenance Instructions
HGU-56/P COMMERCIAL
HELMET ASSEMBLY
Ó2010 GENTEX Corporation

Proper fitting, operation, and maintenance of the helmet is imperative for the safety
of the user.
Before you use or maintain the helmet, read this entire manual thoroughly. Follow all
Warnings and Cautions precisely.
When you replace components or install additional components on Gentex products,
always use genuine factory-new Gentex parts. This will ensure a correct fit and
maintain the safety of the product. Use of non-Gentex parts (salvage, refurbished,
etc.) for replacement or additional installation will void any product warranty and may
compromise the safety of the user.

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Contents
OVERVIEW .......................................1
SECTION 1: INTRODUCTION AND GENERAL DESCRIPTION............1
1-1. SYSTEM DESCRIPTION................................1
1-2 STANDARD COMPONENTS ..............................2
1-3. OPTIONAL COMPONENTS ..............................3
SECTION 2: PREPARATION FOR USE ........................4
2-1. SERVICE UPON RECEIPT ..............................4
2-1.1. Unpacking ....................................4
2-1.2. Inspecting Unpacked Equipment .......................4
2-2. SELECTING HELMET SIZE ..............................5
2-3. INSTALLING OPTIONAL COMPONENTS ......................7
2-3.1 Installing SCL ..................................8
2-3.2 Installing Optional ANVIS Dual Visor Assemblies
(Quick-Disconnect or Direct-Mount)..........................9
2-3.3 Installing ANVIS Attachment Kit
(for Quick-Disconnect ANVIS Dual Visor Assembly) ................10
2-3.4 Installing ANVIS Attachment Kit
(for Direct-Mount ANVIS Dual Visor Assembly) ...................12
2-3.5 Installing High-Contrast Visor .........................16
2-3.6 Installing Flex Boom Microphone .......................18
2-3.7. Installing Coiled Communications Cord ...................20
2-3.8 Installing Maxillofacial Shield (MFS) .....................21
2-4. HELMET FITTING AND OPERATION ........................27
2-5 TRIMMING MFS FOR ANVIS COMPATIBILITY ...................35
2-6. TPL CUSTOM-FITTING................................36
(Continued on next page)

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Contents (continued)
SECTION 3: MAINTENANCE ............................39
3-1. PREVENTIVE MAINTENANCE AND CLEANING ..................39
3-1.1. Pre-flight Inspection ..............................39
3-1.2. Post-flight Inspection .............................39
3-1.3. Cleaning ....................................39
3-2. TROUBLESHOOTING ................................43
3-3. COMPONENT REPLACEMENT............................47
3-3.1 TPL or SCL Cloth Cover ............................48
3-3.2. Energy-Absorbing Liner ...........................49
3-3.3. Retention Assembly ..............................51
3-3.4 Earcups or Earphones.............................53
3-3.5. Microphone Boom/Cord/Swivel Assembly (Wire Boom) ..........55
3-3.6. Flex Boom Microphone ............................56
3-3.7. Communications Cord.............................57
3-3.8. Dual Visor Assembly..............................60
3-3.9 MFS Latch Assembly (on shield) .......................62
3-3.10 MFS Striker (on helmet) ............................63
SECTION 4: REPLACEMENT PARTS ........................64
4-1 STANDARD COMPONENTS .............................64
4-2 OPTIONAL COMPONENTS..............................70

OVERVIEW
This manual provides fitting, operation, and maintenance instructions for the Gentex HGU-56/P
Commercial Helmet Assembly. The manual is divided into the following sections:
•Section 1: Introduction and General Description. This section provides basic
information about the helmet.
•Section 2: Preparation for Use. This section provides instructions for installing optional
components, fitting the helmet, and operating the helmet properly.
•Section 3: Maintenance. This section includes information for cleaning, troubleshooting,
performing preventive maintenance, and replacing components.
•Section 4: Parts List. This section provides information for ordering replacement parts.
SECTION 1: INTRODUCTION AND GENERAL DESCRIPTION
1-1. SYSTEM DESCRIPTION
The HGU-56/P Commercial Helmet Assembly (Figure 1-1) provides ear, eye, and head bump
protection for aircrew personnel. Through a custom-fitting process, the HGU-56/P Helmet
provides a stable mounting base for all modules and components.
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Figure 1-1. HGU-56/P Commercial Helmet Assembly

1-2 STANDARD COMPONENTS
The helmet consists of the following standard components (Figure 1-2):
•Helmet Shell. Provides bump protection for the head via the shock-dampening
energy-absorbing liner.
•Boom and Microphone. Part of the communications system, which also includes two
earphones (one inside each earcup) and a communications cord.
•Earcups. Protect hearing by reducing noise and attenuating some side impacts.
•Retention Assembly. Stabilizes the helmet on the head; consists of earcup
retaining pads, a chinstrap with a buckle, and a nape strap pad with adjustable straps.
•Thermoplastic Liner (TPLâ). Optimizes fit and comfort; can be heat-softened and
custom-fitted if necessary.
•Energy-Absorbing (EA) Liner. Absorbs and reduces impact forces.
•Dual Visor Assembly. Protects the wearer’s eyes from sun glare, flash fires, ballistic
spall, dust, and foreign particles. Includes a clear inner visor and a neutral gray
(sunshade) outer visor.
•Headband Pad Kit. Used when necessary to improve helmet fit.
•Earcup Spacer Pad Kit. Used when necessary to improve earcup fit.
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TPLâis a registered trademark of GENTEX Corporation.
Figure 1-2. Standard Components of HGU-56/P Commercial Helmet
Energy-absorbing liner
TPL
Earcup (earphone inside)
Earcup retaining pad
Dual visor assembly
Boom and microphone
Communications cord
Headband pad kit
Earcup spacer pad kit
Chin strap
Nape pad
Helmet shell

1-3. OPTIONAL COMPONENTS
Optional components (Figure 1-3) include the following:
•ANVIS dual visor assemblies. Options include a quick-disconnect version, which allows
one-handed attachment and removal of the ANVIS mount; and a direct-mount version,
which has a raised area for direct mounting of the ANVIS V-1 mount.
•Super Comfort Liner (SCL). Provides the protective benefits of the TPL, but offers
enhanced comfort; conforms to individual head shapes through body heat to ensure
increased stability while nearly eliminating the need for additional custom-fitting.
•Maxillofacial Shield (MFS). Protects the lower face from rotor wash, flying debris, and
windblast during helicopter operations; has dual side release latches that provide for
positive lock and quick release of the shield from either side of the helmet.
•High-contrast visor. Provides enhanced vision for flying in low-light conditions, such as
snowy, foggy, overcast, hazy or cloudy environments; causes the blue portions of the
visible spectrum to appear black or dark while other colors appear nearly normal; available
for installation as an outer visor on the HGU-56/P.
•Flex boom. Permits ease and flexibility for positioning the microphone.
•36" coiled communications cord. Similar to the standard communications cord, but
coiled for convenience; stretches to approximately 60 inches in length.
•Helmet bag. Larger than standard helmet bags; available in black, woodland camo, ACU
camo, and desert camo (see Page 71 for part numbers); has a thickly padded interior to
protect helmets and accessories; includes a shoulder strap and multiple pockets.
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Figure 1-3. Optional Components
Quick-disconnect
ANVIS dual visor
assembly
Direct-mount
ANVIS dual visor
assembly SCL
MFS Helmet bag
High-contrast
visor, outer
36" coiled cord
Flex boom
Attachment kit for
quick disconnect
ANVIS dual visor
assembly
Attachment kit for
direct-mount ANVIS
dual visor assembly
Hardware kit for flex boom

SECTION 2: PREPARATION FOR USE
2-1. SERVICE UPON RECEIPT
This section contains instructions regarding the tasks to be performed upon receipt of the
helmet. These tasks include unpacking and inspecting unpacked equipment.
2-1.1. Unpacking
1. Open the over pack carton and remove all unit pack cartons. Unit pack cartons are labeled
according to their contents. Open each unit pack carton. Remove the sealed helmet and, if
supplied, the helmet bag.
2. Unseal the bag containing the helmet. Take the helmet, the earcup spacer pad set, the
headband fitting pad set, and the ANVIS mounting kit (if supplied) out of the bag. Remove
the wrapping from the helmet.
3. Open the sealed bag containing the helmet bag (if supplied), and remove the helmet bag.
2-1.2. Inspecting Unpacked Equipment
1. Check the helmet and all included items for any damage incurred during shipment. Report
any damage to your shipper.
2. Check the helmet and all other parts against the packing slip to determine if all parts have
been included. Report any discrepancies immediately to your shipper.
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