EN 3745-801:2024

Aerospace series - Fibres and cables, optical, aircraft use - Test methods -Part 801: Fibre movement under compression

This document specifies a method of measuring the semi loose effect of a semi loose cable.
Pull proof optical contacts are used. The optical contact (ferrule) is longitudinally moving to preserve the optical performance even when cables are pulled.
Consequently, the buffered fibre moves beneath the strength members (called semi loose effect).
This document describes a test methodology to assess the quality of the cable when contact is pulled or pushed.

Luft- und Raumfahrt - Faseroptische Leitungen für Luftfahrzeuge - Prüfverfahren - Teil 801: Faserbewegung unter Druck

Dieses Dokument legt ein Verfahren zur Messung der halbfesten Wirkung eines Kompaktaderkabels fest.
Auszugssichere optische Kontakte werden verwendet. Der optische Kontakt (Ferrule) bewegt sich in Längsrichtung, um die optische Leistung auch bei Kabeln unter Zug aufrechtzuerhalten.
Folglich bewegt sich die gepolsterte Faser unterhalb der Zug /Stützelemente (bezeichnet als halbfeste Wirkung).
Dieses Dokument enthält eine Prüfmethodologie zur Bewertung der Qualität des Kabels, wenn der Kontakt durch Zug oder Druck beansprucht wird.

Série aérospatiale - Fibres et câbles optiques à usage aéronautique - Méthodes d'essais - Partie 801 : Déplacement de la fibre sous compression

Le présent document spécifie une méthode de mesure de l’effet semi-lâche d’un câble semi-libre.
Des contacts optiques résistant à la traction sont utilisés. Le contact optique (ferrule) se déplace longitudinalement pour préserver les performances optiques même lorsque les câbles sont étirés.
En conséquence, la fibre gainée se déplace sous l'armature de renfort (ce qui est appelé « effet semi-libre »).
Le présent document décrit une méthodologie d’essai pour évaluer la qualité du câble lorsque le contact est étiré ou contracté.

Aeronavtika - Optična vlakna in kabli za uporabo v zračnih plovilih - Preskusne metode - 801. del: Premik vlaken pri kompresiji

Ta dokument določa metodo za merjenje pol-ohlapnega učinka kabla s pol-ohlapno strukturo.
Uporabljeni so optični kontakti, ki se v primeru sile ne razdružijo. Optični kontakt (tulka) se premika vzdolžno, s čimer ohrani optično zmogljivost tudi ob vlečenju kablov.
Posledično se pufrano vlakno premika pod togimi elementi (imenovano pol-ohlapni učinek).
Ta dokument opisuje preskusno metodo za ocenjevanje kakovosti kabla ob vlečenju ali potisku kontakta.

General Information

• Status: Published
• Publication Date: 18-Jun-2024
• ICS: 49.090 - On-board equipment and instruments
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 2/S 10 - Optical
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 19-Jun-2024
• Completion Date: 19-Jun-2024
• Ref Project: SIST EN 3745-801:2024 - Aerospace series - Fibres and cables, optical, aircraft use - Test methods -Part 801: Fibre movement under compression

Relations

• Revised: prEN 3745 - Aerospace series - Fibres and cables, optical, aircraft use - Test methods
• Effective Date: 15-Oct-2025

Overview

EN 3745-801:2024 - part of the CEN aerospace series - specifies a test method for measuring fibre movement under compression in semi-loose optical cables for aircraft use. The standard defines how to assess the "semi loose effect" where a buffered fibre slides beneath strength members while a longitudinally moving, pull‑proof optical contact (ferrule) preserves optical performance. EN 3745-801:2024 sets the measurement setup, procedures and pass/fail criteria to evaluate cable quality when the connector is pushed or pulled.

Key topics and requirements

• Scope: Test methodology for semi-loose optical cables (aerospace use) to characterise fibre movement under compression.
• Test specimen preparation:
  • Stabilize specimens at standard test conditions for 24 h (per EN 2591-100).
  • Terminate specimens with specified pull‑proof contacts (LC referenced).
• Connector requirement:
  • Use LC connectors compliant with EN 61754-20 (LC family) or equivalent product-specified pull-proof contacts.
• Apparatus:
  • Light Launch System (LLS) and Light Detection System (LDS) as per EN 2591-100.
  • Patch cords with fixed LC ferrule and mating patch cords.
  • Test fixture capable of applying controlled longitudinal displacement/compression.
  • Note: fixed ferrule may require epoxy in the spring cavity to lock ferrule motion for test control.
• Measurement protocol:
  • Preliminary compression profile at 5 mm/min, sampled every 0.1 mm.
  • Measurement phase at 50 mm/min; optical transmittance measured at 850 nm.
  • Change in attenuation recorded continuously; sampling rate must be at least half the duration of full displacement.
  • Typical push sequence: compress to 0.5 mm, record; further compress to 1.5 mm and record. Repeat cycles (20 cycles per end).
  • Monitor compression force; test bench can be automated or semi-automated.
• Acceptance criterion:
  • Transmittance change shall not exceed ±0.1 dB for each individual compression and between 0.5 mm and 1.5 mm steps.

Practical applications

• Validates optical performance of aerospace optical fibres and semi-loose cables under connector compression and handling stresses.
• Ensures reliable in-flight and ground handling performance for aircraft fibre-optic harnesses, repairable patch panels and line-replaceable units.
• Supports product qualification, supplier testing, and quality control for aerospace cable manufacturers and system integrators.

Who uses this standard

• Aerospace cable and connector manufacturers
• Aircraft electrical/avionics engineers and qualification labs
• Component suppliers for in-flight communications, sensors and data links
• Test houses performing certification and acceptance testing

Related standards

• EN 3745-100 (general test requirements for aerospace optical cables)
• EN 3745-301 (attenuation measurement methods)
• EN 2591-100 and EN 2591-602 (optical connection test methods)
• EN 4533-004 (cleaning/inspection guidance)
• EN 61754-20 (LC connector interface)

Keywords: EN 3745-801:2024, fibre movement under compression, aerospace optical cables, semi loose cable, LC connector, pull-proof optical contacts, attenuation test, Light Launch System, Light Detection System.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2024
Aeronavtika - Optična vlakna in kabli za uporabo v zračnih plovilih - Preskusne
metode - 801. del: Premik vlaken pri kompresiji
Aerospace series - Fibres and cables, optical, aircraft use - Test methods -Part 801:
Fibre movement under compression
Luft- und Raumfahrt - Faseroptische Leitungen für Luftfahrzeuge - Prüfverfahren - Teil
801: Faserbewegung unter Druck
Série aérospatiale - Fibres et câbles optiques à usage aéronautique - Méthodes d'essais
- Partie 801 : Déplacement de la fibre sous compression
Ta slovenski standard je istoveten z: EN 3745-801:2024
ICS:
33.180.10 (Optična) vlakna in kabli Fibres and cables
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 3745-801
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2024
EUROPÄISCHE NORM
ICS 49.090
English Version
Aerospace series - Fibres and cables, optical, aircraft use -
Test methods -Part 801: Fibre movement under
compression
Série aérospatiale - Fibres et câbles optiques à usage Luft- und Raumfahrt - Faseroptische Leitungen für
aéronautique - Méthodes d'essais - Partie 801 : Luftfahrzeuge - Prüfverfahren - Teil 801:
Déplacement de la fibre sous compression Faserbewegung unter Druck
This European Standard was approved by CEN on 5 February 2024.

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, 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, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3745-801:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 General requirements . 4
5 Preparation of specimens . 5
6 LC requirements . 5
7 Apparatus . 5
8 Method . 6
8.1 Preparation . 6
8.2 Change in attenuation protocol . 6
8.3 Installation procedure . 7
8.4 Measurement procedure . 7
8.4.1 Preliminary phase . 7
8.4.2 Measurement phase . 7
8.5 Final measurement . 8

European foreword
This document (EN 3745-801:2024) has been prepared by 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 shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by December 2024, and conflicting national standards shall be
withdrawn at the latest by December 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. CEN 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 document: 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,
Türkiye and the United Kingdom.
1 Scope
This doc
...