Avionics News February 2013 - 30

WIRES, CABLES & CONNECTORS
Continued from page 29

its failure causes delays, unscheduled landings, IFE system
problems, and both nonfatal and
deadly accidents. EWIS was
born in 2007, when the Federal
Aviation Administration officially
recognized wires, cables and connectors as a system critical to the
safety of flight in subpart H of
Federal Aviation Regulations Part
25, making EWIS equal to the
critical systems it powers, connects and controls.
Legally, EWIS requirements
target transport-category aircraft,
which includes most of today’s
business jets, but that doesn’t
mean reliable transmission of
power and data isn’t equally im-

portant to all aircraft. Focused
mainly on maintenance, inspection and repair, EWIS does reach
into shops where wiring harnesses are born, according to Keith
Bachleda, the application engineer for cables and connectors for
EMTEQ.
That’s pronounced EM-tech,
for electrical mechanical technology, and “we ‘heart’ cable,” said
Kerry Stuckart, product manager
for cables, trays and accessories,
who’s been with the company
since 1997. With a Small Business Association loan, Jerry Jendusa, president, started the company in his basement, in 1996.
Today, beyond its 82,000-squarefoot AS9100 and FAA PMA
headquarters in New Berlin, Wis.,
EMTEQ has offices in Europe,

Graphic courtesy of EMTEQ

EMTEQ’s network analyzer measures the performance of a TCAS harness.
30

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february

2013

Brazil and Canada, a facility in
Montana, and an engineering
center in Florida that’s developed
several STCs that include avionics, cabin comfort and power, and
interior and exterior LED lighting
for civilian and military original
equipment manufacturers, repair
centers and integrators.
When designing a custom harness for a customer, EMTEQ addresses all the EWIS performance
standards, from the spacing of
bundle ties to bend radiuses, tension and friction, and vibration
pulling on the wire, cable and
connectors. In routing the bundle,
there must be just enough slack at
the appropriate points to allow for
airframe expansion, contraction
and vibration, but not too much,
which exacts a penalty in weight
and costs. The company designs
and builds a number of integrated
harnesses that distribute power
and data. Picture a huge bundle
of 150 wires and cables starting
at one end of the plane branching
out different components and linereplaceable units throughout the
plane.
First, each strand in the bundle
must bear the electrical load it
will carry or transfer data at the
appropriate frequency for the required distance without exceeding
the allowable attenuation values.
And each one must neither emit
nor fall victim to electromagnetic
interference. Sometimes, a simple
unshielded twisted-pair will do,
where the twists cause the two
fields to cancel each other. After
explaining the right-hand rule of
electronics, Bachleda said “if you

Avionics News February 2013

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