EN 4639-101:2007

Overview

EN 4639-101:2007 is a European standard developed by CEN that specifies the performance and dimensions of optical physical contacts used with the EN 4641-100 cable in aerospace applications. It applies to rectangular, modular, multicontact optical connectors featuring a 1.25 mm diameter ferrule and a removable alignment sleeve holder. The standard ensures reliable operation of these optical contacts over a wide temperature range from -65 °C to 125 °C, addressing the stringent requirements typical of aerospace environments.

This standard forms part of the Aerospace series and is essential for manufacturers and users of optical connectors aimed at aircraft and defense systems, guaranteeing interoperability, durability, and high-quality optical signal transmission.

Key Topics

• Scope & Application
  Defines the performance metrics and mechanical dimensions of physical optical contacts for EN 4641-100 tight structure cable with 125 µm fibre diameter.

• Contact Designation
  Standardizes fibre optic contact types and cable structure compatibility to ensure proper identification and interchangeability.

• Dimensions and Mechanical Properties
  Specifies precise dimensions and tolerances of the optical ferrule and connector components to guarantee accurate alignment and optimal optical performance. Typical spring forces to maintain contact are also defined.

• Technical and Environmental Requirements
  Includes testing protocols based on EN 2591 series to validate endurance, temperature cycling, humidity resistance, salt mist exposure, insertion loss (maximum 0.7 dB), return loss (minimum -21 dB), and mechanical endurance (500 mating cycles).

• Assembly and Maintenance Instructions
  Provides detailed guidelines for cleaning optical faces and sleeves, recommended tooling in line with MIL-I-81969/14, termination procedures including epoxy curing, fibre cleaving, polishing, and inspection protocols to ensure consistent quality during assembly and maintenance.

Applications

• Aerospace Optical Communication Systems
  Critical for connecting optical fibers in aircraft avionics where reliable data transfer under extreme temperature fluctuations is mandatory.

• Defense and Military Equipment
  Suitable for harsh environments requiring high durability optical connectors with robust mechanical and environmental resistance.

• High-Performance Modular Optical Connectors
  Used in equipment requiring multicontact configurations for compact, modular optical interconnect solutions designed to meet aerospace-grade reliability.

• Optical Fibre Cable Termination
  Enables termination of EN 4641-100 cable which is designed for rugged, tight structure fibres benefitting aerospace optical networks.

Related Standards

• EN 4641-100 - Specifies the product standard for tight structure optical cables with a 1.8 mm outer diameter, applicable to the cable used with these optical contacts.

• EN 4639-001 & EN 4639-002 - Provide the technical specifications and list of product standards for optical rectangular modular connectors with 1.25 mm ferrules used in aerospace applications.

• EN 2591 Series - Defines test methods that assess durability, environmental resistance, and performance of electrical and optical connection elements.

• MIL-I-81969/14 - U.S. military standard referenced for tooling required during contact insertion and extraction.

• TR 4647 - Aerospace technical report describing proper termination and cleaning procedures to maintain optical contact integrity.

This standard is indispensable for aerospace engineers, system integrators, and connector manufacturers focused on high-reliability optical connectivity solutions in extreme operating conditions. Adhering to EN 4639-101:2007 ensures optimal optical performance, extended component life, and compliance with industry best practices.