Aerospace Cable
Harnesses
To support high-reliability, quality wire harness and cable assemblies manufacturing,
assemblies use mil-spec qualified RF connectors and wire. Hand soldering is performed by J-STD-001 certified
solders, and all cable crimping is performed using calibrated tooling.
Military Custom Cable Assemblies, Aerospace Cable Assemblies, Cable Assemblies
Prototyping and Design include Coaxial Cable Assemblies, Multiconductor Cable Assemblies, Flat Ribbon Cable
Assemblies, Moulded Cable Assemblies and Small Pitch Assemblies.
Technological trends in military and aerospace cable assemblies over the last five
years have included weight reduction, increased use of data bus architectures, denser electronic packaging,
increased transmission speed requirements, and the increased use of fibre optics.
Weight reduction, particularly in airframe design, has been key to increasing
performance and fuel efficiency. The Boeing 787 is composed of 50 percent composites, 20 percent aluminum, 15
percent titanium, and 15 percent other materials. This has translated into composite MIL-DTL 38999 connectors
from Souriau being used in the wire harnesses. Amphenol supplies special high-performance, thermoplastic
cable bundle clamps. This has led to both the use of lighter weight and thinner wall insulation in milaero
cable products, and the downsizing of connectors to smaller shell sizes.
Data bus architecture is another major trend in airframes. Using the Boeing Dreamliner
as an example again, the 787 is utilizing a version of Ethernet—Avionics Full Duplex Switched Ethernet
(AFDX), ARINC 664—to transmit data between the flight deck and the aircraft systems. AFDX can be run on
either twisted-pair copper cable or fibre optic cable. This has reduced the number of wire harnesses/wire
runs, and has eliminated the use of hydraulic power (and thus hydraulic lines) to control the plane. This has
the further advantage of not draining power from the engines for the hydraulics. Overall, Boeing eliminates
60 miles of copper wire on each plane, compared to the wiring requirements of older airframes.
Denser packaging of the electronics into milaero products has also led to more
potential electro-magnetic interference (EMI). Aerospace fibre optics is one approach to solving some of
these problems, and has the added benefit of being immune to electronic countermeasures and electro-magnetic
pulses (EMP).
Increasing requirements for transmission speed and bandwidth improvements are
frequently met by fibre optic cables. It is more difficult to meet the requirements with copper wire,
however. This has required the use of better insulation materials, better shielding, precise twisting of
pairs, and contact design that minimizes signal loss and interference.
On the business side, many of the OEMs on milaero programs are subcontracting a
significant portion of the build. This has resulted in some purchasing volumes for components subdivided over
several subcontractors. One aspect of the subcontracting is the complexity that it can add to a program. Part
of the delay on the Boeing 787 has been due to coordinating the activities of their subcontractors, and the
subcontractors grappling with building more complete subsystems for delivery to the Boeing’s assembly
facility in Washington state.
What does the future hold? From a technology standpoint, the current trends will
continue and will present more challenges to the connector, cable, and cable assemblies manufacturers. They
will not only need to understand the technology, but be able to measure and verify the performance of the
assemblies to make sure they meet the strict parameters and rigours of the milaero environments.
The commercial aerospace industry should do fairly well over the next five years. If
driven by nothing else, current fleets around the world are aging quickly and will require replacement.
Despite the economic pressures on the industry, the airlines will also have to continue to update their
fleets to achieve better fuel economies.
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