Cables & Cable Assemblies

Case Study: Military Avionics Equipment Manufacturer - Interface LRU for Fighter Aircraft

Fighter Aircraft

The Challenge: The customer needed to integrate optical interconnects within a very densely packed Line Replaceable Unit (LRU) for a military aircraft application.  Specifically, a top-mounted MIL-C-38999 style external disconnect needed to route down and around several circuit assemblies and mate to an on-board parallel optical transceiver. 

The Solution:

  • An easily installed pre-formed optical assembly
  • The first assembly of this type to be successfully qualified
  • Passed all tests where competitive solutions failed

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Unlike copper interconnects, exceeding the minimum bend radius of optical fibers can result in excessive loss and reduction of margin in the optical power budget.  For a mil-aero application, this would have a direct impact on reliability.  If, as in this application, installers are not specifically trained in fiber optics, there are risks of snagging the optical cable as the card assemblies are inserted. 

The customer supplied Gore with a 3-D CAD model that depicted a precise, 3-D routing path for the optical interconnect.  Working directly from this CAD file, Gore created a drop-in solution based on a pre-formed optical cable assembly.   A requirement for no EMI emission or susceptibility through the optical port was met by a Gore-developed EMI backshell.  Finally, Gore qualified the assembly through a battery of harsh shock, vibration, temperature and other requirements. 

Gore’s unique technology:

  • Removed the burden and risk of fiber optic installation
  • Met military qualification

Application Need Requirement Gore's Enabling Technology

Connect transceiver on a card to external LRU interface
MT interface to MIL-C-38999
MT, MIL-T-29504 termination expertise
Densely packed LRU with highly constricted routing
 Predefined 3D routing Preformed buffer and jacket combination from customer CAD input
Installers untrained in fiber optics Eliminate risk of overstressing fiber (min bend radius) Preformed bends
Harsh shock, vibration, temperature Mil qualification Materials and termination technology, mil qual experience
EMI requirements No emission or susceptibility through optical port  Custom EMI backshell components