EN 3733-003:2008

Overview

EN 3733-003:2008 is a CEN product standard for aerospace circular single‑channel optical plug connectors. It defines the characteristics of plug connectors that use ferrules and a self‑locking ring coupling, designed for single‑core fibre optic cable manufactured to EN 4532. The connector family is rated for continuous operation up to 150 °C and is intended for aerospace electrical and optical interconnection systems.

Key topics and requirements

• Scope and compatibility
  • Applies to plug connectors for cables to EN 4532; mating compatibility and spare‑part relationships are specified (see EN 3733‑002 for full product listings).
  • Connectors terminated with EN 4532 cable are compatible only with similarly terminated mating connectors.
• Mechanical and materials
  • Connector shell material: nickel‑copper alloy.
  • Maximum mass: 18.2 g (terminated overall length assumes a maximum gap of 1 mm between crimp sleeve and rear nut).
  • Dimensional details are provided in the standard’s figure(s).
• Optical performance limits
  • Initial insertion loss (before conditioning): ≤ 0.6 dB (measured at 810 nm, overfill launch).
  • Post‑conditioning insertion loss: ≤ 0.85 dB; optical discontinuity threshold typically set at 0.85 dB with minimum discontinuity durations and counts controlled.
  • Discontinuities > 20 ns are restricted by the test criteria.
• Environmental and mechanical testing
  • Damp heat, cyclic: 10 cycles with specific insertion loss criteria.
  • Shock: severity 300 g, method A; multiple shocks per axis.
  • Vibration: defined PSD profiles, modified Method B and optional high‑level vibration per MIL‑STD‑810F (gunfire spectra) for severe conditions.
  • Cable attachment effectiveness: axial load (200 N), cable pulling, cyclic flexing, torsion and axial compression tests with prescribed loads and cycles.
• Designation and marking
  • Standard prescribes a product designation format and cross‑reference to test classes and polarization (EN 3733‑001/002).

Applications and users

• Typical use cases:
  • Aircraft and aerospace platforms requiring high‑temperature optical interconnects for avionics data links, sensors, cameras and flight‑critical optical cabling.
  • Environments where resistance to shock, vibration and cyclic humidity is mandatory.
• Primary users:
  • Aerospace connector designers and manufacturers
  • Qualification and test engineers
  • Procurement specialists and system integrators specifying optical interconnects to aerospace standards
  • Maintenance and certification authorities validating connector replacements or upgrades

Related standards

• EN 3733‑001 - Technical specification (interface dimensions, test tables, qualification)
• EN 3733‑002 - List of product standards (product types, codification)
• EN 3733‑004 / 005 / 006 - Receptacle product standards
• EN 3733‑007 - Ferrule product standard
• EN 3733‑008 - Plug sub‑assembly product standard
• EN 4532 - Single‑core optical cable technical specification
• EN 2591 / EN 2591‑100 - Test methods for optical elements
• MIL‑STD‑810F - High‑level vibration (referenced for gunfire vibration spectra)

Keywords: EN 3733-003:2008, aerospace optical connector, circular single channel, plug connector, EN 4532, self‑locking ring, 150 °C, ferrule, fibre optic connector, aerospace standards.