Size, weight, and power consumption are the main drivers in aircraft design for better fuel efficiency and lower operating costs. Fiber applications have a lot of advantages; does that mean that copper already belongs to the past? Not really. The following article below goes into detail regarding the fiber vs copper debate. Read more here: http://bit.ly/Article-FiberVsCopper

1. A question of faith? Copper vs fiber in
modern commercial aircraft
In the last couple of years, fiber optic cables have emerged as the hottest new trend in the realm of
aircraft cabling. Easy connectivity, faster transfer rates and lightweight materials seemed to make
the copper cables of the past obsolete. But are they really the end-all-be-all solution? This article
examines the different applications and shows ways that copper might still have a future in aircraft
cabling. Read the full piece below!
The world of commercial aviation and aircrafts
has changed significantly in the last decade. While
it was always an important factor – commercial
aircraft now run almost completely on
information. Mechanical controls are becoming
a concept of the past with engineers adopting
MEA (more electric aircraft) into their new designs.
Embedded computers seem to be the answer
in tackling the increased signal processing and
control load demands.
Electronics reign supreme, from increasingly
accurate and detailed radar systems to better
sensors analyzing in real-time what is going on
at any given moment. But not only the pilots and
engineers profit from this development – mid-air
internet access and in-flight entertainment are
only some of the new amenities being offered to
passengers along with high-def video and a myriad
of services.
Why High Speed?
Another interesting development has been the
“decentralization” of processing power. This
means that instead of having one main processor
responsible for every calculation, there
are now more, but smaller processors
being used. Distributed avionics, as it is called,
spread the risk, but also require flawless
communication between the distributed boxes.
In order to utilize the potential, high processing
loads are being used.
This, in turn translates into faster embed-
ded computers and faster interconnections
between boxes, actuators, and sensors.
Ethernet stands out as the preferred protocol.While
there are alternatives such as IEEE 1394 and USB,
Ethernet offers the best performance required to
meet the 1Gb/s (and 10Gb/s soon) load demand.
Why SWaP?
SWaP describes the main drivers for aircraft
designers - size, weight, and power
consumption. This mighty combination is the path
to better fuel efficiency and lower operating costs.
Weight reduction can be achieved not only by the
obvious reduction in metal weight, but
smaller connectors with lightweight
compositeshellsratherthanheaviermetalshellsare
complemented by cables and harnessing
components that are likewise smaller and lighter
are small things with a big impact.
Actually, just by replacing the aluminum
enclosures with composite one, it is possible to
save up to 40% in weight. One aspect to consider
though, is that smaller and lighter is not enough
– the bottom line is that the enclosures primarily
have to withstand the common dangers in
aviation: environmental, vibration, among others.
Advantages of Fiber: Sprint or distance?
Fiber applications have existed along with
high-bandwidth or matched-impedance
copper cables for decades now. There are quite a
few very important differences, though: For copper
cables, higher data rates mean shorter transmission
distances. They are also more prone to
electromagnetic interference which may
www.aircraft-cabling.com

2. require extra shielding, thus adding
weight and size. This issue first brought
designers to explore the possibilities of fiber optics.
Some of the main benefits are:
• Longer transmission distances – even
though interconnect distances in aircraft can be
relatively short, passenger cabins in commercial
aircraft can still present end-to-end challenges
for copper cabling that optic fiber does not have.
• Smaller size and weight – While
fiber-to-copper comparisons depend on
specific cable configurations, consider
“generic”baseline cables: A duplex fiber-optic cable
offers approximately 25% space savings and 50%
weight savings over a shielded PVC Cat 5e cable.
• EMI immunity – Since optical fibers are
inherently immune to electrical noise – neither
receivingnorradiatingenergy–theycanbeapplied
without concern for EMI control.The potential need
toshieldcoppercablesonlydrivesupsizeandweight.
But fiber optics actually also help in increasing
the physical longevity of the network. In doing so,
higher data rates may be implemented thereby
allowing for new services. This puts one major
worry to rest: that there will be new services
rendering an existing cable infrastructure obsolete.
Fiber optics will not be outdated any time soon and
allow for every service imaginable.
OneSizeFitsAll?CabinSystemsandFiberOptics
One example pro fiber is the video system in
passenger aircrafts. Airlines have mostly shift-
ed from the strategically placed overhead
screens on to individual seat-back screens.
This did not only allow more comfort, but also
individually tailored services and on-demand
services with personal playlists, choics of movie and
television as well as games and shopping. The
advantage of fiber-optic cable here is that they
can be run directly from the server to the screen.
This “home-run architecture” eliminates the
intermediate switches, zone boxes, and seat
electronics required with a copper system. Weight
savings per seat is about 60% over legacy copper
systems. Beyond the reduction in complexity, a
fiber optic system can have bandwidth to spare.
Multimode fibers can easily carry data rates of
>10Gb/s across the length of even the largest
wide-body aircraft.
One case where this approach can be observed
is the Lumexis FTTS (Fiber-To-The-Screen) sys-
tem, which will be available soon on the 737-
800, 787-900, and 787 MAX aircraft. The system
uses 50/125 optical fibers home run to each seat-
back screen. In this scenario, there are usually
interconnections found at the side walls or floor to
make installation and maintenance easier. One side
would be situated at the server, the other one at
the seat end.
These so-called production breaks make it
possible for cables that are running from the
server to side wall and from side wall to screen
to be standardized. The longer cables in the
side wall or under the floor will vary in length,
depending on the distance from server to seat.
Another advantage is the range of options
available for aircraft designers since there are a
number of industry-standard aviation connectors
for most fiber-optic inserts. The most common
are easily ceramic ferule physical-contact termini.
These include ARINC, EN4165, and MIL-
DTL-38999 Series III styles. Another interesting
approach has been developed recently by TE
Connectivity with the MC801 connector,
which combines industry-standard ARINC 801
termini and a 38999-style shell. In the end, the
modularity which one wants to apply is one of the
deciding factors in choosing a connector type.
A high-fiber-count connector simplifies
connectivity, but limits modularity. For repeat-
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3. ed mating/unmating at the side wall or low leg
interface, a termini with a protected
expanded-beam interface provides high
mating-cycle durability and easy cleaning. ARINC
845, which covers expanded beam technologies,
recently selected TE’s PRO BEAM EB16 terminus for
such applications. The terminus fits size 16 cavities
in industry-standard connector inserts.
Either/Or? Both have a place and time
So, with the long list of advantages for fiber optics
it seems only a question of time when copper will
be a thing of the past, right? Not really. Right now, it
seems that both will continue to co-exist for a while
and each system has its application.
Copper remains the comfortable system that has
been tried and tested while fiber obviously
handles high-bandwidth demands and longer
distances better. For the end-user, all that matters is
a seamless and comfortable experience data, audio
and video processes and both copper and optical
connectivity have to be able to bridge and
consistently accommodate any production breaks
that might occur.
The truth is that both technologies are still
evolving and both technologies are still
offering new options for increased data loads.
However, in the long run, fiber seems to be
slowly making headway as its weight
savings, high bandwidth capability, and longer
transmission distances become ever more
important.
Are you involved in aircraft cabling or do you still
need impulses for optimal cabling solutions in your
aircraft design? Then come and join us at the up-
coming international conference aircraft cabling,
taking place 01 - 03 December, 2015 at the
Privathotel Lindtner in Hamburg, Germany.
Discuss these and other topics, meet experts and
engage in discussions about the future of aircraft
cabling.
For more information and one of the last seats, visit:
www.aircraft-cabling.com
www.aircraft-cabling.com