EN 4863:2023

Aerospace series - Rotorcraft immersion suits - Requirements, testing and marking

This document specifies requirements for immersion suits for use by helicopter crew members and passengers in the event of a ditching or water impact, to ensure minimum levels of performance. It applies to immersion suits for use by adults only.

Luft- und Raumfahrt - Eintauchanzüge für Drehflügler - Anforderungen, Prüfung und Kennzeichnung

Série aérospatiale - Combinaisons de protection thermique en cas d’immersion de giravion - Exigences, essais et marquage

Le présent document spécifie les exigences relatives aux combinaisons de protection thermique en cas d'immersion destinées à être utilisées par les membres d'équipage et par les passagers des hélicoptères en cas d'amerrissage forcé ou d'impact avec un plan d'eau, afin de garantir des niveaux minimaux de performance. Il s'applique uniquement aux combinaison de protection thermique en cas d'immersion destinées à être utilisées par des adultes.

Aeronavtika - Potopne obleke za posadko v rotoplanu - Zahteve, preskušanje in označevanje

General Information

• Status: Published
• Publication Date: 09-May-2023
• ICS: 13.340.10 - Protective clothing
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 12/WG 2 - Ditching Equipment
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 10-May-2023
• Completion Date: 10-May-2023
• Ref Project: kSIST FprEN 4863:2022 - Aerospace series - Rotorcraft immersion suits - Requirements, testing and marking

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 4863:2021
01-november-2021
Aeronavtika - Potopne obleke za posadko v rotoplanu - Zahteve, preskušanje in
označevanje

Aerospace series - Rotorcraft immersion suits - Requirements, testing and marking

Ta slovenski standard je istoveten z: prEN 4863
ICS:
13.340.10 Varovalna obleka Protective clothing
49.020 Letala in vesoljska vozila na Aircraft and space vehicles in
splošno general
oSIST prEN 4863:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 4863:2021
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oSIST prEN 4863:2021
DRAFT
EUROPEAN STANDARD
prEN 4863
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2021
ICS 13.340.10
English Version
Aerospace series - Rotorcraft immersion suits -
Requirements, testing and marking

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-

STAN.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 4863:2021 E

worldwide for CEN national Members.
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Contents Page

European foreword ...................................................................................................................................................... 3

Introduction .................................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 7

4 Classification................................................................................................................................................... 11

5 Requirements ................................................................................................................................................. 11

5.1 General.............................................................................................................................................................. 11

5.2 Design ................................................................................................................................................................ 11

5.3 Size and fit ....................................................................................................................................................... 12

5.4 Materials and components ........................................................................................................................ 12

5.5 Resistance to temperature variation ..................................................................................................... 15

5.6 Flammability ................................................................................................................................................... 15

5.7 Wear and tear ................................................................................................................................................. 15

5.8 Conspicuity ...................................................................................................................................................... 15

5.9 EBS ...................................................................................................................................................................... 18

5.10 Other optional accessories ........................................................................................................................ 18

5.11 Ergonomic performance ............................................................................................................................. 19

5.12 Additional requirements for integrated immersion suits ............................................................. 21

5.13 Immersion suit system performance and compatibility requirements ................................... 26

6 Testing .............................................................................................................................................................. 29

6.1 Visual inspection ........................................................................................................................................... 29

6.2 Nominal values and tolerances ................................................................................................................ 29

6.3 Order of testing .............................................................................................................................................. 29

6.4 Fuel resistance of materials and components .................................................................................... 29

6.5 Magnetic properties testing ...................................................................................................................... 29

6.6 Temperature cycling.................................................................................................................................... 30

6.7 Flammability test .......................................................................................................................................... 30

6.8 Wear and tear ................................................................................................................................................. 31

6.9 Retroreflective material application ..................................................................................................... 33

6.10 Ergonomic performance ............................................................................................................................. 33

6.11 Additional tests for integrated immersion suits ............................................................................... 45

6.12 Immersion suit system performance and compatibility ................................................................ 47

6.13 Crew equipment compatibility ................................................................................................................ 48

6.14 Reporting ......................................................................................................................................................... 50

7 Marking ............................................................................................................................................................ 50

8 Information supplied by the manufacturer ........................................................................................ 51

Annex A (informative) Guidelines for manufacturers and users relating to the different

categories of immersion suit .................................................................................................................... 53

A.1 General.............................................................................................................................................................. 53

A.2 Operational application of immersion suit categories.................................................................... 53

Bibliography ................................................................................................................................................................. 56

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European foreword

This document (prEN 4863:2021) has been prepared by the Aerospace and Defence Industries

Association of Europe – Standardization (ASD-STAN).

After enquiries and votes carried out in accordance with the rules of this Association, this document has

received the approval of the National Associations and the Official Services of the member countries of

ASD-STAN, prior to its presentation to CEN.
This document is currently submitted to the CEN Enquiry.
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Introduction

This technical document prescribes the minimum standards of design and performance for rotorcraft

immersion suits, used to reduce cold shock on initial immersion and provide thermal protection

following evacuation or escape from a rotorcraft.

The technical document aims to ensure that the equipment user is able to perform normal activities

during flight and to carry out the necessary emergency procedures, whilst being provided with an

appropriate level of protection under foreseeable conditions of use. It aims to ensure that the

equipment presents a minimal hazard in relation to escape from the rotorcraft, and that the equipment

has no detrimental effect on the health and safety of the user or on the performance of other equipment.

It is assumed for the purpose of this document that the immersion suit is donned prior to boarding the

rotorcraft.

Rotorcraft immersion suits may be designed to be worn with an approved rotorcraft constant wear

lifejacket or may be designed to incorporate the functionality of a lifejacket in which case the wearing of

a separate lifejacket is not required.

This document is applicable to all rotorcraft. Rotorcraft include helicopters, tilt rotor/wing and

gyroplanes. For the purpose of this document, the term helicopter is used generically hereinafter.

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1 Scope

This technical document specifies requirements for immersion suits for use by helicopter crew

members and passengers in the event of a ditching or water impact, to ensure minimum levels of

performance. It applies to immersion suits for use by adults only.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

EN 4856, Rotorcraft - Emergency Breathing Systems (EBS) - Requirements, testing and marking

EN 4862:—, Rotorcraft - Constant Wear Lifejackets - Requirements, testing and marking

EN 4886, Aerospace series - Rotorcraft - Liferafts for operations in hostile sea areas - Requirements,

testing and marking

EN 14225-1:2017, Diving suits - Part 1: Wet suits - Requirements and test methods

EN ISO 811, Textiles - Determination of resistance to water penetration - Hydrostatic pressure test

(ISO 811)

EN ISO 1421, Rubber- or plastics-coated fabrics - Determination of tensile strength and elongation at

break (ISO 1421)

EN ISO 2411, Rubber- or plastics-coated fabrics - Determination of coating adhesion (ISO 2411)

EN ISO 4674-1, Rubber- or plastics-coated fabrics - Determination of tear resistance - Part 1: Constant

rate of tear methods (ISO 4674-1)

EN ISO 7854, Rubber- or plastics-coated fabrics - Determination of resistance to damage by flexing

(ISO 7854)

EN ISO 9227, Corrosion tests in artificial atmospheres - Salt spray tests (ISO 9227)

EN ISO 11092, Textiles - Physiological effects - Measurement of thermal and water-vapour resistance

under steady-state conditions (sweating guarded-hotplate test) (ISO 11092)

EN ISO 12402-7, Personal flotation devices - Part 7: Materials and components - Safety requirements and

test methods (ISO 12402-7)

EN ISO 12402-8, Personal flotation devices - Part 8: Accessories - Safety requirements and test methods

(ISO 12402-8)

EN ISO 12894, Ergonomics of the thermal environment - Medical supervision of individuals exposed to

extreme hot or cold environments (ISO 12894)
Under preparation. Current stage is: prEN 4862:2021.
Under preparation.
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EN ISO 13934-1, Textiles - Tensile properties of fabrics - Part 1: Determination of maximum force and

elongation at maximum force using the strip method (ISO 13934-1)

EN ISO 13935-2, Textiles - Seam tensile properties of fabrics and made-up textile articles - Part 2:

Determination of maximum force to seam rupture using the grab method (ISO 13935-2)

EN ISO 13937-4, Textiles - Tear properties of fabrics - Part 4: Determination of tear force of tongue-

shaped test specimens (Double tear test) (ISO 13937-4)

ISO 105-A02, Textiles — Tests for colour fastness — Part A02: Grey scale for assessing change in colour

ISO 105-E02, Textiles — Tests for colour fastness — Part E02: Colour fastness to sea water

ISO 105-X12, Textiles — Tests for colour fastness — Part X12: Colour fastness to rubbing

ISO 188, Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests

ISO 3801, Textiles — Woven fabrics — Determination of mass per unit length and mass per unit area

ASTM D1655, Specification for aviation turbine fuels
CIE 015, Colorimetry

DEF STAN 91-091, Turbine Fuel, Kerosine Type, Jet A-1; NATO Code: F-35; Joint Service Designation:

AVTUR

EASA, Certification Specifications and Acceptable Means of Compliance for Large Aeroplanes, CS-25,

Book 1 – Appendix F
EASA, ETSO-C85b, Survivor locator lights
IATA, Guidance material (Kerosene Type), NATO Code F-35

IMO, Resolution A.658(16), Use and fitting of retro-reflective materials on life-saving appliances

IMO, International Life-Saving Appliance (LSA) Code, adopted by Resolution MSC.48(66), (as amended)

IMO, Resolution MSC.81(70), (adopted on 11 December 1998) Revised recommendation on testing of life-

saving appliances
MIL-STD-3009, Lighting, aircraft, night vision imaging system (NVIS) compatible

SAE ARP5825, Design requirements and test procedures for dual mode exterior lights

SAE AS 4492A, Survivor locator lights
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3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
lifejacket

garment or device which, when correctly worn and used in water will provide the user with buoyancy

positioned to provide protection from drowning and increase the likelihood of survival and rescue

3.2
helicopter constant wear lifejacket

lifejacket worn on the body throughout a helicopter flight over water, provided to protect the user in

the event of a ditching or water impact
3.3
buoyancy chamber
inflatable component of a lifejacket or integrated immersion suit
3.4
immersion suit

garment designed to protect the user’s body from the cooling effects of unintended immersion in water

Note 1 to entry: Cooling effects include cold shock and hypothermia.

Note 2 to entry: An immersion suit may be integrated or worn with a separate constant wear lifejacket.

3.5
integrated immersion suit
immersion suit that incorporates the functionality of a lifejacket
3.6
buoyancy element

inflatable chamber incorporated into an integrated immersion suit that, when inflated, provides the suit

with the functionality of a lifejacket
3.7
helicopter immersion suit

immersion suit worn on the body throughout a helicopter flight, provided to protect the user in the

event of a ditching or water impact
3.8
immersion suit system

helicopter immersion suit (with or without thermal insulation) and its components and accessories

including either a constant wear lifejacket or buoyancy element and/or emergency breathing system, as

applicable
3.9
hood

covering for the head and neck with an opening for the face, worn for protection against cold

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3.10
glove

covering for the hand which may have separate parts for each finger and the thumb, worn for

protection against cold
3.11
thermal insulation

material layer used in an immersion suit to reduces heat flow, thus provided protection against cold

3.12
underclothing
clothes worn under a helicopter immersion suit
3.13
emergency breathing system
EBS

system that allows a person to breathe underwater, overcoming the need to breath-hold for the

complete duration of an underwater escape from a helicopter, that can be deployed under emergency

conditions
3.14
rotorcraft

heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or

more rotors
3.15
helicopter

rotorcraft that, for its horizontal motion, depends principally on its engine-driven rotors

3.16
ditching

controlled emergency landing on water, deliberately executed in accordance with Rotorcraft Flight

Manual procedures, with the intent of abandoning the rotorcraft as soon as practical

3.17
water impact

helicopter contact with water that is unintentional or exceeds the ditching capability of the helicopter

for water entry
3.18
crew member
person assigned by an operator to perform duties on board an aircraft
3.19
hardware

lifejacket components such as structural closures and adjusters and multi-eyelet guides used with

lacing
3.20
manual inflation system

means of inflation achieved by a person operating a mechanism that actively releases stored gas into

the buoyancy chamber(s)
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3.21
fully inflated

inflation achieved by using the manual inflation system (stored gas) with no subsequent deflation

3.22
oral inflation system

means of inflation achieved by a person blowing expired air into the buoyancy chamber(s)

3.23
overpressure relief valve

safety device used to limit the pressure in an inflatable system, to avoid the likelihood of destruction

caused by excessive pressure
3.24
sprayhood

cover that can be brought in front of the face, incorporating an area of transparent material, used to

protect the airways from water and wave splash, intended to increase the likelihood of survival in

rough water conditions
3.25
survivor locator light

device which emits light intended to aid in the location of the user in an emergency

3.26
whistle

device which, when blown by mouth, produces an audible sound intended to aid in the location of the

user
3.27
lifting loop
device which facilitates manual recovery of a person from water
3.28
buddy line

length of cord or webbing which can be tied or otherwise fixed to another person or to that person’s

lifejacket or other objects, so as to keep the user in the vicinity of that person or object, aiding in the

location of the user
3.29
retroreflective material

material that reflects light beams back to their point of origin with a low level of scattering

3.30
infrared

electromagnetic radiation at the red end of the spectrum at wavelengths from 800 nm to 1 mm (longer

than those of visible red light but shorter than microwaves)
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3.31
personal locator device
PLD

device carried on the body that is able to transmit a signal to enable electronic detection and location of

a person in the water

Note 1 to entry: In the maritime environment a PLD may be known as an Autonomous Maritime Rescue Device

(AMRD).
3.32
escape buoyancy

buoyancy of an equipment combination, with the lifejacket or buoyancy element uninflated, that must

be overcome when escaping from an immersed helicopter

Note 1 to entry: It includes the inherent buoyancy of the components of the immersion suit system and entrapped

air but excludes the inflated buoyancy elements.
3.33
hypothermia
condition where body core temperature is below 35 °C
3.34
cold shock

short transitory phase lasting about 2 min to 3 min upon sudden immersion in cold water and

characterized by reduced breath-holding ability and an uncontrollable hyperventilation accompanied

by other cardio-respiratory distress
3.35
heat strain

increase of body temperature induced by sustained heat stress which cannot be fully compensated by

temperature regulation or activation of thermoeffective activities in response to heat stress, which

cause sustained changes in the state of other, non-thermal, regulatory systems
3.36
thermal resistance
insulation

temperature difference between the two faces of a material divided by the resultant heat flux per unit

area in the direction of the gradient

Note 1 to entry: The dry heat flux may consist of one or more conductive and radiant components. Thermal

resistance R , expressed in square metres kelvin per watt, is a quantity specific to textile materials or composites,

which determines the dry heat flux across a given area in response to a steady applied temperature gradient.

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4 Classification

There are four categories of immersion suit system with different thermal insulation, defined in Table 1.

Table 1 — Helicopter immersion suit system categories
Category 1 Category 2 Category 3 Category 4
Insulation level Immersion suit Immersion suit Immersion suit Immersion suit
system without system with low system with system with high
inherent inherent medium inherent inherent
insulation insulation insulation insulation
Sea temperatures
relating to ≥ 12 ≥ 7 ≥ 2 < 2
intended use (°C)
NOTE Helicopter immersion suits are hereinafter referred to as immersion suits.

Protection from drowning is provided either by the use of a helicopter constant wear lifejacket worn

with the immersion suit, or by the immersion suit incorporating a buoyancy element that has the

functionality of a lifejacket (integrated immersion suit).

Guidance and background relating to the use of immersion suits and the different categories of

protection is provided in Annex A (informative).
5 Requirements
5.1 General

5.1.1 Immersion suits may be designed for dedicated use by crew members only, for dedicated use by

passengers only, or for use by crew members and passengers.

5.1.2 The immersion suit system shall not adversely affect the health or hygiene of the user.

5.2 Design
5.2.1 The immersion suit shall comprise at least the following:
• a dry coverall garment;
• wrist seals;
• neck and/or face seal;
• a closure system;
• integral socks or boots.

5.2.2 A combination of an immersion suit and accessories shall not impair the performance of the

system. This shall be established by testing the immersion suit and accessories in combination, in

accordance with 6.1, 6.10, 6.11, 6.12 and 6.13 as applicable.
The requirements for accessories are identified in Table 2.

5.2.3 The immersion suit shall include an integral or separate hood to provide thermal insulation to

the head. Testing shall be carried out in accordance with 6.1.
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5.2.4 The immersion suit shall include gloves to protect the hands. Gloves shall be either permanently

attached or tethered to the immersion suit. Testing shall be carried out in accordance with 6.1.

5.2.5 The immersion suit shall not contain any component nor use any method of component

attachment which in normal use is likely to cause injury to the user or damage the suit when tested in

accordance with 6.10, 6.11, 6.12 and 6.13.
Table 2 — Immersion suit accessories
Accessory Mandatory Optional Requirement
Inherent thermal insulation layer
5.11.6, 5.11.7
Hood x 5.2.3
Gloves x 5.2.4
Sprayhood 5.12.11
Survivor locator light
x 5.12.1
Whistle
x 5.12.2
Lifting loop 5.12.3
Buddy line
5.12.4
Retroreflective material x 5.8.2
EBS 5.9, 5.13
Other x 5.10, 5.13
Dependent upon the category of immersion suit system.
Mandatory for immersion suits with integral lifejacket functionality.

EBS are only mandatory for helicopter offshore operations [European Commission Regulation (EU) No

965/2012, amended by Commission Regulation (EU) 2016/1199, SPA.HOFO.165(c)]. EBS may or may not

be attached to the immersion suit.
5.3 Size and fit

The design of the immersion suit shall allow tailoring to fit the individual user or, where suits are not

individually tailored, the size range shall be satisfactory to at least fit the test subject size range defined

in 6.10.2.
Testing shall be carried out in accordance with 6.1, 6.10.4.
5.4 Materials and components
5.4.1 General

The choice of materials used shall be such that, when stowed in accordance with the relevant

instructions, neither the immersion suit nor its attached equipment shall be liable to become

unserviceable through material deterioration or chafing, or from any other cause. All materials used

shall be compatible with the complete immersion suit system.

All fabric samples including seam samples shall be pre-conditioned by temperature cycling in

accordance with 6.6.
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5.4.2 Fuel resistance

All exterior structural materials, fabrics, typical seams, seals and components of the immersion suit

shall be resistant to the damaging effects of aviation fuel (Jet A1 in accordance with DEF STAN 91-091,

ASTM D1655 and IATA Guidance material (Kerosene Type), NATO Code F-35).

Testing shall be carried out in accordance with the fuel resistance test (6.4). There shall be no leakage

during the hydrostatic test and the tensile seam strength shall be at least 150 N per 50 mm width using

the grab method given in EN ISO 13935-2.
5.4.3 Fabric flammability

The outer fabric used in the construction of the immersion suit shall as a minimum meet the vertical

test of EASA CS-25 Appendix F Part 1 (a)(1)(ii) (or as amended).
The test shall be conducted on new fabric without any pre-treatment.
5.4.4 Fabric thermal conductivity
5.4.4.1 Outer fabrics

Where required in accordance with 5.11.6.2, the thermal conductivity of the outer fabrics used in the

construction of the immersion suit shall be measured in fresh water.

Testing shall be carried out in accordance with the test method described in EN 14225-1:2017, Annex A.

Measurements shall be carried out on three samples of each material. Each sample shall be in the form

of a cylindrical sleeve 210 mm high and 150 mm diameter, to give a surface area exposed to the heat

flow of 0,1 m .

The tank in which the apparatus is immersed shall be at a uniform water temperature between 10 °C

and 15 °C and the difference between the water temperature within the apparatus and the external

water temperature shall be between 25 °C and 30 °C.
Each sample shall be tested at a pressure of 1 bar absolute only.
5.4.4.2 Insulating material

Where required in accordance with 5.11.6.2, the thermal conductivity of any insulating material that is

not an outer fabric shall be tested in accordance with the thermal resistance requirements of

EN ISO 11092.
Measurements shall be carried out on three samples of each material.
5.4.5 Tensile strength of seams

The tensile strength of seams shall be of at least 200 N per 50 mm width. The seam shall not leak when

samples are subjected to a hydrostatic test according to EN ISO 811 at a rate of 100 mm/min up to a

1 000 mm water head. Then carry out a tensile seam strength test according to EN ISO 13935-2. The

tensile strength shall be measured on separate samples using specimens of at least 60 mm width and

with at least 100 mm of material on each side of the test point, with four similar seams for each type of

...