Avionics News February 2015 - 21

Wiring and coaxial cables need their own attention
"That's especially true for how and where coax cables are routed
and shielded," Robinson continued. "It has to be done right for the
particular combination of system and aircraft."
Antennae, goes the consensus, are always "a huge challenge,"
Robinson said. "We go to extra lengths to make sure they're grounded
and work with the airframe. It always helps to have a good relationship with the OEM. Depending on how complex the installation is,
the manufacturer may have some specific directions, and you don't
want to deviate from that because they did the testing."
The mix of materials can add challenges that complicate antenna
installation.
"Grounding planes, working with new metal or composites - it
all has to be done right for the equipment and the helicopter," Robinson said.
Helicopter avionics technicians shared the need to assure that cable runs, shielding and ground connections avoid all-aircraft no-nos
like kinks, nicks in insulation, and proper attention to shielding for
coax carrying current or RF. The ground connections can be of particular concern on general aviation helicopters that use the aluminum
airframe as the common ground.
For more advanced helicopters - particularly ones with more complex electrical systems - the ground wiring installed for various systems employ solid connections, protection from the elements to avoid
corrosion, and must be securely mounted to avoid movement or flexing that could produce chafing of the insulation and the problems bare
wires can spark. The higher the number of distinct harnesses and the
more connections they carry, the more important these considerations
become - and the greater the potential for time-consuming troubleshooting should wiring contribute to a system problem or failure.
Tooling can be another issue that challenges installation.
"When you have special considerations, you need to be sure you
have the equipment to do the job right," Robinson said. "You want
to make sure your work is good and have the equipment needed
because so many helicopters fly in jobs and you don't want them to
be on the ground."
As noted by one technician who works predominantly on helicopter avionics and electrical systems, "Helicopters fly differently, they
land differently, maneuver differently - all because they generate lift
and thrust so differently. Wiring and vibration issues can be a threat
to any aircraft, but some that seem inconsequential or nonexistent in
fixed-wing aircraft carry grave implications in a helicopter."
The most-basic worry is common across almost all aircraft: keeping electricity flowing.
"It's vital to know and understand the helicopter's electrical system, how it works, how it's constructed," Robinson said. "As helicopters get more like some business jets, the systems become more
complicated and challenging to troubleshoot."
As with all aircraft with electrical systems, the simpler the system
the fewer the single points of failure that tend to exist. The more sophisticated the aircraft, the greater the likelihood that it faces more

potential failure options, but the backup systems capable of handling
the crisis conditions.
Helicopter-specific technologies continue to advance:
TSO C-194 HTAWS
In April 2014, as part of some new rulemaking, the FAA mandated
that all helicopter operators follow enhanced procedures for flying in
weather, at night and in remote locations. One of the rule changes will
require the helicopter EMS community to use the latest technology to
help avoid terrain and obstacles by 2017.
Like terrain awareness and warning systems for fixed-wing aircraft, the advent of helicopter TAWS, or HTAWS, raised the effectiveness of a tool that already helped dramatically reduce controlledflight-into-the-ground accidents.
Typically based on a WAAS GPS receiver and an extensive
ground-feature database, HTAWS does not actively "look ahead" of
the aircraft the way radar altimeters look down and ahead with radar.
Instead, these systems use rapid position- and altitude-data processing from the GPS engine to calculate height, location and speed as the
aircraft flies across the ground.
The best systems alert pilots of approaching terrain, wires or
other hazards through the use of high-resolution terrain databases,
flight path data and very sophisticated algorithms. Producers of
HTAWS devices continue to refine their technology, and as a result,
the frequency of nuisance alerts continues to decrease with each
new model.
Recently, the FAA added HTAWS as a requirement for helicopter emergency medical services operations, with a special HTAWS
requirement that improves on data below 500 feet - below where
even low-flying helicopters usually fly.
Like all helicopter avionics, these devices must meet the appropriate TSO - as mentioned, including DO-160F. One such system
comes from Aspen Avionics and its EFD1000H, which includes a
special vibration mount to help the package meet DO-160F helicopter vibration standards.
One system comes from Honeywell, which leveraged its groundbreaking Enhanced Ground Proximity Warning System to become
the first avionics maker to win approval for a new self-contained
HTAWS package under TSO C-194, with Sandel checking in as
well in the form of its self-contained ST3400H HeliTAWS system.
New levels of sensitivity, new color standardizing across different
platforms and improved database information contribute to improved
protections for helicopter operations down in the lower altitudes they
often fly.
Since both of these - and other systems from PFDs to WAAS
navigators to MFDs - employ a WAAS GPS engine to provide position data, meeting the different needs of antenna mounting must,
shops stress, adhere to the information from the airframe maker and
the avionics manufacturer. Avoiding interference is the goal here,
versus the need to isolate from excess, vibration-sensitive electronics mounted in panels and on remote shelves. q
avionics news

*

february

2015

21



Avionics News February 2015

Table of Contents for the Digital Edition of Avionics News February 2015

Point of Communication
AEA Now
The View from Washington
International News and Regulatory Updates
Rotorcraft Avionics
Member Profile
Cool City Obsession
Staying Power
Member Profile
What’s Working?
My Life in Avionics (part 2)
Business Basics
Before & After
A Conversation With...
Tools and Test Equipment
What’s New
Marketplace Classifieds
Avionics News February 2015 - Intro
Avionics News February 2015 - Cover1
Avionics News February 2015 - Cover2
Avionics News February 2015 - 1
Avionics News February 2015 - 2
Avionics News February 2015 - 3
Avionics News February 2015 - Point of Communication
Avionics News February 2015 - 5
Avionics News February 2015 - AEA Now
Avionics News February 2015 - 7
Avionics News February 2015 - 8
Avionics News February 2015 - 9
Avionics News February 2015 - 10
Avionics News February 2015 - 11
Avionics News February 2015 - The View from Washington
Avionics News February 2015 - 13
Avionics News February 2015 - International News and Regulatory Updates
Avionics News February 2015 - 15
Avionics News February 2015 - 16
Avionics News February 2015 - 17
Avionics News February 2015 - Rotorcraft Avionics
Avionics News February 2015 - 19
Avionics News February 2015 - 20
Avionics News February 2015 - 21
Avionics News February 2015 - Member Profile
Avionics News February 2015 - 23
Avionics News February 2015 - 24
Avionics News February 2015 - 25
Avionics News February 2015 - Cool City Obsession
Avionics News February 2015 - 27
Avionics News February 2015 - 28
Avionics News February 2015 - 29
Avionics News February 2015 - 30
Avionics News February 2015 - 31
Avionics News February 2015 - Staying Power
Avionics News February 2015 - 33
Avionics News February 2015 - 34
Avionics News February 2015 - 35
Avionics News February 2015 - 36
Avionics News February 2015 - 37
Avionics News February 2015 - Member Profile
Avionics News February 2015 - 39
Avionics News February 2015 - 40
Avionics News February 2015 - 41
Avionics News February 2015 - What’s Working?
Avionics News February 2015 - 43
Avionics News February 2015 - 44
Avionics News February 2015 - 45
Avionics News February 2015 - My Life in Avionics (part 2)
Avionics News February 2015 - 47
Avionics News February 2015 - 48
Avionics News February 2015 - 49
Avionics News February 2015 - Business Basics
Avionics News February 2015 - 51
Avionics News February 2015 - 52
Avionics News February 2015 - Before & After
Avionics News February 2015 - A Conversation With...
Avionics News February 2015 - 55
Avionics News February 2015 - Tools and Test Equipment
Avionics News February 2015 - 57
Avionics News February 2015 - 58
Avionics News February 2015 - 59
Avionics News February 2015 - 60
Avionics News February 2015 - 61
Avionics News February 2015 - 62
Avionics News February 2015 - 63
Avionics News February 2015 - What’s New
Avionics News February 2015 - 65
Avionics News February 2015 - 66
Avionics News February 2015 - 67
Avionics News February 2015 - 68
Avionics News February 2015 - 69
Avionics News February 2015 - Marketplace Classifieds
Avionics News February 2015 - 71
Avionics News February 2015 - 72
Avionics News February 2015 - Cover3
Avionics News February 2015 - Cover4
https://www.nxtbook.com/allen/avne/60-10
https://www.nxtbook.com/allen/avne/60-9
https://www.nxtbook.com/allen/avne/60-8
https://www.nxtbook.com/allen/avne/60-7
https://www.nxtbook.com/allen/avne/60-6
https://www.nxtbook.com/allen/avne/60-5
https://www.nxtbook.com/allen/avne/60-4
https://www.nxtbook.com/allen/avne/60-3
https://www.nxtbook.com/allen/avne/60-2
https://www.nxtbook.com/allen/avne/60-1
https://www.nxtbook.com/allen/avne/59-12
https://www.nxtbook.com/allen/avne/59-11
https://www.nxtbook.com/allen/avne/59-10
https://www.nxtbook.com/allen/avne/59-9
https://www.nxtbook.com/allen/avne/59-8
https://www.nxtbook.com/allen/avne/59-7
https://www.nxtbook.com/allen/avne/59-6
https://www.nxtbook.com/allen/avne/59-5
https://www.nxtbook.com/allen/avne/59-4
https://www.nxtbook.com/allen/avne/59-3
https://www.nxtbook.com/allen/avne/59-2
https://www.nxtbook.com/allen/avne/59-1
http://www.brightcopy.net/allen/avne/58-12
http://www.brightcopy.net/allen/avne/58-11
http://www.brightcopy.net/allen/avne/58-10
http://www.brightcopy.net/allen/avne/58-9
http://www.brightcopy.net/allen/avne/58-8
http://www.brightcopy.net/allen/avne/58-7
http://www.brightcopy.net/allen/avne/58-6
http://www.brightcopy.net/allen/avne/58-5
http://www.brightcopy.net/allen/avne/58-4
http://www.brightcopy.net/allen/avne/58-3
http://www.brightcopy.net/allen/avne/58-2
http://www.brightcopy.net/allen/avne/58-1
http://www.brightcopy.net/allen/avne/57-12
http://www.brightcopy.net/allen/avne/57-11
http://www.brightcopy.net/allen/avne/57-10
http://www.brightcopy.net/allen/avne/57-9
http://www.brightcopy.net/allen/avne/57-8
http://www.brightcopy.net/allen/avne/57-7
http://www.brightcopy.net/allen/avne/57-6
http://www.brightcopy.net/allen/avne/57-5
http://www.brightcopy.net/allen/avne/57-4
http://www.brightcopy.net/allen/avne/57-3
http://www.brightcopy.net/allen/avne/57-2
http://www.brightcopy.net/allen/avne/57-1
http://www.brightcopy.net/allen/avne/56-12
http://www.brightcopy.net/allen/avne/56-11
http://www.brightcopy.net/allen/avne/56-10
http://www.brightcopy.net/allen/avne/56-9
http://www.brightcopy.net/allen/avne/56-8
http://www.brightcopy.net/allen/avne/56-7
http://www.brightcopy.net/allen/avne/56-6
http://www.brightcopy.net/allen/avne/56-5
http://www.brightcopy.net/allen/avne/56-4
http://www.brightcopy.net/allen/avne/56-3
http://www.brightcopy.net/allen/avne/56-2
http://www.brightcopy.net/allen/avne/56-1
http://www.brightcopy.net/allen/avne/55-12
http://www.brightcopy.net/allen/avne/55-11
http://www.brightcopy.net/allen/avne/55-10
http://www.brightcopy.net/allen/avne/55-9
http://www.brightcopy.net/allen/avne/55-8
http://www.brightcopy.net/allen/avne/55-7
http://www.brightcopy.net/allen/avne/55-6
http://www.brightcopy.net/allen/avne/55-5
http://www.brightcopy.net/allen/avne/55-4
http://www.brightcopy.net/allen/avne/55-3
http://www.brightcopy.net/allen/avne/55-02
http://www.brightcopy.net/allen/avne/55-01
http://www.brightcopy.net/allen/avne/54-12
http://www.brightcopy.net/allen/avne/54-11
http://www.brightcopy.net/allen/avne/54-10
http://www.brightcopy.net/allen/avne/54-9
http://www.brightcopy.net/allen/avne/54-8
http://www.brightcopy.net/allen/avne/54-7
http://www.brightcopy.net/allen/avne/54-6
http://www.brightcopy.net/allen/avne/54-5
http://www.brightcopy.net/allen/avne/54-4
http://www.brightcopy.net/allen/avne/54-3
http://www.brightcopy.net/allen/avne/54-2
http://www.brightcopy.net/allen/avne/54-1
http://www.brightcopy.net/allen/avne/53-12
http://www.brightcopy.net/allen/avne/53-11
http://www.brightcopy.net/allen/avne/53-10
http://www.brightcopy.net/allen/avne/53-9
http://www.brightcopy.net/allen/avne/53-8
http://www.brightcopy.net/allen/avne/53-7
http://www.brightcopy.net/allen/avne/53-6
http://www.brightcopy.net/allen/avne/53-5
http://www.brightcopy.net/allen/avne/53-4
http://www.brightcopy.net/allen/avne/53-3
http://www.brightcopy.net/allen/avne/53-2
http://www.brightcopy.net/allen/avne/53-1
http://www.brightcopy.net/allen/avne/52-12
http://www.brightcopy.net/allen/avne/52-11
http://www.brightcopy.net/allen/avne/52-10
http://www.brightcopy.net/allen/avne/52-9
http://www.brightcopy.net/allen/avne/52-8
https://www.nxtbook.com/allen/avne/52-7
https://www.nxtbook.com/allen/avne/52-6
https://www.nxtbook.com/allen/avne/52-5
https://www.nxtbook.com/allen/avne/52-4
https://www.nxtbook.com/allen/avne/52-3
https://www.nxtbook.com/allen/avne/52-2
https://www.nxtbook.com/allen/avne/52-1
https://www.nxtbook.com/allen/avne/51-12
https://www.nxtbook.com/allen/avne/51-11
https://www.nxtbook.com/allen/avne/51-10
https://www.nxtbook.com/allen/avne/51-9
https://www.nxtbook.com/allen/avne/51-8
https://www.nxtbook.com/allen/avne/51-7
https://www.nxtbook.com/allen/avne/51-6
https://www.nxtbook.com/allen/avne/51-5
https://www.nxtbook.com/allen/avne/51-4
https://www.nxtbook.com/allen/avne/51-3
https://www.nxtbook.com/allen/avne/51-2
https://www.nxtbook.com/allen/avne/51-1
https://www.nxtbook.com/allen/avne/50-12
https://www.nxtbook.com/allen/avne/50-11
https://www.nxtbook.com/allen/avne/50-10
https://www.nxtbook.com/allen/avne/50-9
https://www.nxtbook.com/allen/avne/50-8
https://www.nxtbook.com/allen/avne/50-7
https://www.nxtbook.com/allen/avne/50-6
https://www.nxtbook.com/allen/avne/50-5
https://www.nxtbook.com/allen/avne/50-4
https://www.nxtbook.com/allen/avne/50-3
https://www.nxtbook.com/allen/avne/50-2
https://www.nxtbook.com/allen/avne/50-1
https://www.nxtbook.com/allen/avne/49-12
https://www.nxtbook.com/allen/avne/49-11
https://www.nxtbook.com/allen/avne/49-10
https://www.nxtbook.com/allen/avne/49-9
https://www.nxtbook.com/allen/avne/49-8
https://www.nxtbook.com/allen/avne/49-7
https://www.nxtbook.com/allen/avne/49-6
https://www.nxtbook.com/allen/avne/49-5
https://www.nxtbook.com/allen/avne/49-4
https://www.nxtbook.com/allen/avne/49-3
https://www.nxtbook.com/allen/avne/49-2
https://www.nxtbook.com/allen/avne/49-1
https://www.nxtbook.com/allen/avne/48-12
https://www.nxtbook.com/allen/avne/48-11
https://www.nxtbookmedia.com