SIST EN 4723:2015

Aerospace series - Standardized measurement methods for comfort and living space criteria for aircraft passenger seats

This European Standard specifies requirements and measurement methods for the assessment of passenger living space and comfort. Its aim is to improve the passenger comfort quality of aircraft cabins and provide measurement methods to compare cabin seat layouts and seats.

Luft- und Raumfahrt - Standardisierte Meßmethoden für Komfort und Living Space Kriterien bei Passagiersitzen im Flugzeug

Série aérospatiale - Mesure standardisée du confort et de léspace de vie des sièges passagers dávion

Aeronavtika - Standardizirane metode za merjenje kriterija udobja in življenjskega prostora potniških sedežev v zračnih plovilih

Ta evropski standard določa zahteve in merilne metode za oceno
življenjskega prostora in udobja potnikov. Njegov namen je izboljšati kakovost letalskih kabin v povezavi z udobjem za potnike
ter podati merilne metode za primerjavo postavitve kabinskih sedežev in kakovosti sedežev.

General Information

• Status: Published
• Public Enquiry End Date: 19-Aug-2014
• Publication Date: 18-Oct-2015
• ICS: 49.095 - Passenger and cabin equipment
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 06-Oct-2015
• Due Date: 11-Dec-2015
• Completion Date: 19-Oct-2015
• Ref Project: EN 4723:2015 - Aerospace series - Standardized measurement methods for comfort and living space criteria for aircraft passenger seats

Overview

EN 4723:2015 - published by CEN as part of the Aerospace series - defines standardized measurement methods for comfort and living space criteria for aircraft passenger seats. Approved 19 March 2015, this European Standard specifies requirements and repeatable measurement procedures to assess passenger living space and comfort in aircraft cabins. Its primary aim is to improve passenger comfort quality and to provide objective methods to compare cabin seat layouts and individual seats.

Key topics

The standard focuses on clear technical definitions and measurement methods for both geometric living-space metrics and subjective comfort-related parameters. Major topics include:

• Reference points and geometry
  • Cushion Reference Point (CRP), Seat Reference Point (SRP), Seat Measurement Reference Point (SMRP/SCRP) and H‑point definitions and measurement methods.
• Living space (spatial) metrics
  • Pitch and 3‑D living space
  • Shin clearance (SHC), knee space (KS), foot space (FS)
  • Shoulder obstruction height (SOH), visual space (VS)
  • Table height, armrest length/width/height, seat width between armrests, bed length/width in full recline
• Comfort metrics
  • Armrest top height over cushion (TACH), cushion height above cabin floor (CHoF)
  • Average bed angle in full recline, headrest thickness and traverse path
  • Seat depth, backrest angle, seat bottom pressure mapping/distribution (BPD)
  • Foam hardness and integrated seat climate considerations
• Measurement rigor
  • Defined measurement methods to ensure repeatability and comparability across seat designs and cabin layouts.

Practical applications

EN 4723:2015 provides practical value for anyone needing objective, repeatable comfort and space data:

• Seat manufacturers - design validation, R&D benchmarking and product claims based on standardized metrics.
• Aircraft OEMs and interior integrators - layout optimization, ergonomic trade-offs and compliance demonstrations.
• Airlines - cabin configuration selection, passenger experience benchmarking and retrofit decision-making.
• Test laboratories and certification bodies - repeatable test procedures for independent evaluation and comparison.
• Human factors and comfort researchers - standardized metrics for studies correlating ergonomics with passenger satisfaction.

Related standards

Normative references cited in EN 4723:2015 include:

• EN ISO 1856 - compression set for flexible cellular materials
• SAE AS8049B - performance standard for aircraft seats (transport/rotorcraft)
• SAE J826 - devices for defining/measuring seating accommodations
• ASTM D3574 - test methods for flexible cellular materials

Using EN 4723:2015 supports consistent, repeatable measurement and comparison of aircraft passenger seats and cabin layouts - essential for designing comfortable, competitive cabin interiors.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2015
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SURVWRUDSRWQLãNLKVHGHåHYY]UDþQLKSORYLOLK
Aerospace series - Standardized measurement methods for comfort and living space
criteria for aircraft passenger seats
Luft- und Raumfahrt - Standardisierte Meßmethoden für Komfort und Living Space
Kriterien bei Passagiersitzen im Flugzeug
Série aérospatiale - Mesure standardisée du confort et de léspace de vie des sièges
passagers dávion
Ta slovenski standard je istoveten z: EN 4723:2015
ICS:
49.095 Oprema za potnike in Passenger and cabin
oprema kabin equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 4723
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2015
EUROPÄISCHE NORM
ICS 49.095
English Version
Aerospace series - Standardized measurement methods
for comfort and living space criteria for aircraft passenger
seats
Série aérospatiale - Mesure standardisée du confort et Luft- und Raumfahrt - Sandardisierte Meßmethoden
de l'espace de vie des sièges passagers d'avion für Komfort und Living Space Kriterien bei
Passagiersitzen im Flugzeug
This European Standard was approved by CEN on 19 March 2015.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 4723:2015 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Abbreviations and definitions . 6
4 Requirements . 7
4.1 General . 7
4.2 Comfort and living space metrics . 7
5 Technical/geometric definitions and measurement methods . 9
5.1 General . 9
5.2 Cushion reference point (CRP) . 9
5.2.1 CRP definition . 9
5.2.2 CRP measurement method . 9
5.3 Seat reference point (SRP) . 10
5.3.1 SRP definition . 10
5.3.2 SRP measurement method . 10
5.4 Seat measurement reference point (SMRP) / Seat comfort reference point (SCRP) . 11
5.4.1 SMRP/SCRP definition . 11
5.4.2 SMRP / SCRP measurement method . 11
5.5 H-point . 11
5.5.1 H-point definition. 11
5.5.2 H-point measurement method . 12
6 Living space . 12
6.1 Pitch and 3-D living space . 12
6.1.1 Pitch and 3-D living space definition . 12
6.1.2 Pitch and 3-D living space measurement method . 13
6.2 Shin clearance (SHC) . 13
6.2.1 SHC definition . 13
6.2.2 SHC measurement method . 13
6.3 Shoulder obstruction height (SOH) . 14
6.3.1 SOH definition . 14
6.3.2 SOH measurement method . 14
6.4 Table height over bottom cushion edge (TH) . 15
6.4.1 TH definition . 15
6.4.2 TH measurement method . 15
6.5 Visual space (VS) . 15
6.5.1 VS definition . 15
6.5.2 VS measurement method . 16
6.6 Knee space (KS) . 16
6.6.1 KS definition . 16
6.6.2 KS measurement method . 16
6.7 Foot Space (FS) . 17
6.7.1 FS definition . 17
6.7.2 FS measurement method . 17
6.8 Bed length in full recline position . 17
6.8.1 Bed length in full recline position definition . 17
6.8.2 Bed length in full recline measurement method . 18
6.9 Armrest length (ARL) . 18
6.9.1 ARL definition . 18
6.9.2 ARL measurement method . 18
6.10 Armrest width in total (ARW) . 19
6.10.1 ARW definition . 19
6.10.2 ARW measurement method . 19
6.11 Seat width between armrests (SWAR) . 19
6.11.1 SWAR definition . 19
6.11.2 SWAR measurement methods . 20
6.12 Armrest height over compressed cushion height (ACH) . 20
6.12.1 ACH definition . 20
6.12.2 ACH measurement method . 20
6.13 Bed width at elbow level (43 in / 1 092,2 mm from end of bed) in full recline position . 20
6.13.1 Bed width at elbow level in full recline position definition . 20
6.13.2 Bed width at elbow level in full recline position measurement method . 21
6.14 Bed width at shoulder level . 21
6.14.1 Bed width at shoulder level definition. 21
6.14.2 Bed width at shoulder level measurement method . 22
7 Comfort . 22
7.1 Armrest top height over seat bottom cushion (TACH) . 22
7.1.1 TACH definition . 22
7.1.2 TACH measurement method. 23
7.2 Cushion height above cabin floor level (CHoF) . 23
7.2.1 Cushion height above cabin floor level definition . 23
7.2.2 Cushion height above cabin floor level measurement method . 23
7.3 Average bed angle in full recline position . 23
7.3.1 Average bed angle in full recline position definition . 23
7.3.2 Average bed angle in full recline position measurement method . 24
7.4 Headrest thickness (HT) . 24
7.4.1 Headrest thickness definition . 24
7.4.2 Headrest thickness measurement method . 25
7.5 Traverse path of headrest including extreme positions . 25
7.5.1 Traverse path of headrest including extreme positions definitions . 25
7.5.2 Traverse path of headrest including extreme positions measurement method . 25
7.6 Seat depth . 26
7.6.1 Seat depth definition . 26
7.6.2 Seat depth measurement method . 26
7.7 Backrest angle to seat bottom cushion (with and w/o recline) . 26
7.7.1 Backrest angle to seat bottom cushion (with and w/o recline) definition . 26
7.7.2 Backrest angle to seat bottom cushion (with and w/o recline) measurement method . 27
7.8 Seat bottom pressure mapping / distribution (BPD) . 27
7.8.1 Seat bottom pressure mapping definition . 27
7.8.2 Seat bottom pressure mapping measurement method . 28
7.9 Foam hardness. 28
7.9.1 Foam hardness definition . 28
7.9.2 Foam hardness measurement method . 28
7.10 Integrated seat climate definition . 28
7.10.1 Integrated seat climate definition . 28
7.10.2 Integrated seat climate measurement method. 28

European foreword
This document (EN 4723:2015) 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 European
Standard has received the approval of the National Associations and the Official Services of the member
countries of ASD, prior to its presentation to CEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2016, and conflicting national standards shall
be withdrawn at the latest by March 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
1 Scope
This European Standard specifies requirements and measurement methods for the assessment of
passenger living space and comfort. Its aim is to improve the passenger comfort quality of aircraft
cabins and provide measurement methods to compare cabin seat layouts and seats.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 1856, Flexible cellular polymeric materials — Determination of compression set (ISO 1856)
SAE AS8049B, Performance Standard for Seats in Civil Rotorcraft, Transport Aircraft, and General
1)
Aviation Aircraft
1)
SAE J826, Devices for Use in Defining and Measuring Vehicle Seating Accommodations
ASTM D3574, Standard Test Methods for Flexible Cellular Materials — Slab, Bonded, and Molded
2)
Urethane Foams
1)
Published by: SAE National (US) Society of Automotive Engineers (http://www.sae.org/).
2)
Published by: ASTM National (US) American Society for Testing and Materials (http://www.astm.org/).
3 Abbreviations and definitions
For the purposes of this document, the following abbreviations and definitions apply.
A/C Aircraft
ACH Armrest height over compressed cushion height
ARL Armrest length
ARW Armrest width
ATD Anthropomorphic test dummy
BPD Seat bottom pressure distribution / mapping
CAD Computer-aided design
CCD Compressed cushion datum
CHoF Cushion height over floor level
CRP Cushion reference point
E/C Economy Class
e.g. exempli gratia (for example)
FS Foot space
H-point Hip-point
HR Headrest
HT Headrest thickness
KS Knee space
LR Long range
P/C Premium Class
PAX Passenger
SAE Society of automotive engineers
SCRP Seat comfort reference point
SHC Shine clearance
SOH Shoulder obstruction height
SMRP Seat measurement reference point
SRP Seat reference point
SWAR Seat width between armrests
TACH Armrest top height over seat bottom cushion
TH Table height over bottom cushion
TTL Taxi-take off-landing
VS Visual space
w/o Without
4 Requirements
4.1 General
For the aim of this document, the aircraft coordinate system is shown in Figure 1.

Figure 1 — Aircraft coordinate system
4.2 Comfort and living space metrics
Compliance with airworthiness requirements, e.g. passageways, minimum aisle widths between
armrests etc. are mandatory.
Comfort and living space criteria are often mixed up. Table 1, Table 2 and Table 3 indicate the category
each criterion belongs to.
Table 1 — Economy class passenger seats
Living space Comfort
Economy class seat metrics
Pitch Armrest height relative to cushion height
3-D living space Seat surface climate
Shin clearance at 60°, 45° Cushion height above cabin floor level
Shin clearance at 35° for LR A/C only Seat depth
Shoulder obstruction height Backrest angle to seat bottom cushion (with and w/o recline)
Table height over bottom cushion edge Headrest thickness
Visual space Traverse path of headrest including extreme positions
Knee space For seats with kinematics and hinge point in the backrest
traverse path of headrest including extreme positions for basic
and hinged position
Clearance height below seat in front Seat pan pressure mapping
Length of armrest Headrest type (hammock, movable x-ways, integrated in
backrest foam)
Width of armrest Foam hardness
Seat width between armrests
Usable seat bottom cushion width between armrests
Ingress/egress at 28 in (711,2 mm), 30 in (762 mm), 32 in
(812,8 mm) pitch, each with backrest table
deployed/undeployed at no and full recline

Table 2 — Premium class passenger seats lie flat
Living space Comfort
Lie flat business class metrics
Shoulder obstruction height Armrest height relative to cushion height
Pitch Seat height
Table height over bottom cushion edge Cushion height above cabin floor level in upright (TTL) mode
3-D living space Seat surface climate
Visual space Total seat depth in full recline position
Knee space Average bed angle in full recline position
Bed length in full recline position Headrest thickness
Seat bottom width in upright (TTL) position Traverse path of headrest including extreme positions
Bed width at elbow level 43 in (1 092,2 mm) from end of bed in Backrest angle to seat bottom cushion (with and w/o recline)
full recline position
Bed with at shoulder level 60 in (1 524 mm) from end of bed in Seat pan pressure mapping
full recline position
Length of armrest Headrest type (hammock, movable x-ways, integrated in
backrest foam)
Width of armrest Foam hardness
Seat width between armrests
Usable seat bottom cushion width between armrests
Table 3 — Premium class passenger seats full flat
Living space Comfort
Full flat/full horizontal business class metrics
Shoulder obstruction height Armrest height relative to cushion height
Pitch Seat height
3-D living space Seat surface climate
Table height over bottom cushion edge Cushion height above cabin floor level in upright (TTL) mode
Visual space Total seat depth in full recline position
Knee space Headrest thickness
Bed length in full recline position Traverse path of headrest including extreme positions
Seat bottom width in upright (TTL) position Backrest angle to seat bottom cushion (with and w/o recline)
Bed width at elbow level 43 in (1 092,2 mm) from end of bed in Seat pan pressure mapping
full recline position
Living space at elbow level in full recline position Headrest type (hammock, movable x-ways, integrated in
backrest foam)
Bed width at shoulder level 60 in (1 524 mm) from end of bed Foam hardness
in full recline position
Length of armrest
Width of armrest
Seat width between armrests
Usable seat bottom cushion width between armrests
5 Technical/geometric definitions and measurement methods
5.1 General
This clause specifies the different geometrical points from which measures are taken. Measuring
methods are indicated below each of the measure explanations and figures. They shall be used to
provide an objective and reproducible result for each seat measured. Measurements shall be carried out
as indicated using anthropomorphic dummies (95%ile, 50%ile male and 5%ile Japanese female)
according to SAE AS8049B if not stated differently. In case of non-availability, humans matching the
anthropomorphic data may be used. Measures shall be taken in an upright and fully reclined position.
5.2 Cushion reference point (CRP)
5.2.1 CRP definition
The cushion reference point (CRP), see Figure 2, is defined as the intersection of the plane of the
uncompressed top of the seat cushion with the plane perpendicular to the seat cushion, which touches
the most forward surface of the uncompressed centre of the seat back.
If a lumbar device is provided, and if it alters the position of the CRP, then the most extended position
(most forward position of the CRP) must be considered.

Key
1 Uncompressed cushions centre line
2 Plane perpendicular to seat cushion touching most forward surface of uncompressed centre of seat back
3 Cushion reference point (CRP)
4 Top of track
Figure 2 — Cushion reference point (CRP)
5.2.2 CRP measurement method
Place a thin, but rigid sheet of metal or plastic on top of the uncompressed seat bottom cushion and
place a back square /tri-square with a long upper leg on top. Move the back square /tri-square towards
the uncompressed centre of the backrest cushion until it touches the most forward position of the
backrest cushion, be it a fully extended lumbar support or in the case of no lumbar support, the backrest
cushion itself. The point of intersection between the prolonged line of the contact to the backrest
cushion and the plane of the uncompressed seat bottom cushion perpendicular to it marks the cushion
reference point.
5.3 Seat reference point (SRP)
5.3.1 SRP definition
The seat reference point (SRP), see Figure 3, is the intersection of the compressed cushion datum (CCD)
and the back tangent line of a seat occupied by a 75 kg to 80 kg (160 lb to 180 lb) subject or 50%ile
male anthropomorphic test dummy (ATD). The methods achieving SRP data are derived from
SAE AS8049B.
Key
1 Compressed seat cushion lowest point (for H-point method plane 97 mm below H-point)
2 Seat reference point (SRP)
3 Top of track
Figure
...