Avionics News April 2015 - 34

TROUBLESHOOTING TIPS
Continued from page 33

"A solid understanding of Ohm's law is
key to good troubleshooting. The better
you understand the fundamentals, the better you will be at doing your job. When
you're dealing with electricity, there's a
traceability path to everything. If you can
apply a high level of logic, it makes troubleshooting much easier."

The composites conundrum

One area that seems to give technicians
fits is dealing with composite aircraft and
airframe components.
"Composite aircraft and airframes can
be a real problem to troubleshoot, especially when it comes to having proper ground
points," explained Steve Wysong, president

of Wysong Enterprises. "You have to make
sure you have a good ground-plane for the
antennas to operate properly.
"Unlike a metal airframe, when you have
composites, you have to manually create
these metal-to-metal grounding connections during the assembly of the airframe
and installation of the antennas. If that becomes compromised, then you can get intermittent connection issues that will cause
problems with the unit's performance.
"If you don't know about this potential
issue, you can spend a lot of time troubleshooting everything but the antenna's
ground. You have to step back and look at
the aircraft, then begin to analyze each part
of that particular system and eliminate the
things that would not cause this problem.
Sometimes, it's just a simple process of
elimination."

Stop problems before they start

There's no better way to cut down on
troubleshooting time than to eliminate
those troubles in the first place. And that
goes double for sophisticated projects
like installing an ADS-B system.
"Getting the ADS-B compliant report
from the FAA before you deliver the aircraft to the customer is huge," explained
Kirk Fryar, president of Sarasota Avionics. "That way, the customer doesn't get
a scary phone call or letter from the FAA
saying their aircraft is not compliant.
"That's why we always test fly every
ADS-B installation and complete the compliance reporting checklist before delivery.
We just did one today. When we got to altitude, we saw we were not getting correct
GPS, LAT/LON data input. The transponder was set for another ADS-B system, so
the GPS/nav/comm was not receiving the
correct data to send the ADS-B data. We
would not have been able to spot that issue without the FAA compliance report. It
saved the customer a trip back to our shop
and saved us a good deal of additional
troubleshooting time."

Take a hard look at software

"Another thing to make sure you
check, especially when doing an installation, is software," Fryar said. "It's not
uncommon for big problems to be solved
or avoided by just making sure you have
the right software protocol in the unit.
"Most of the time, it's all in the installation manual - how to set up this device
- but there are times when you have to
guess. Software versions are not the kind
of thing you'll be very successful with by
guessing. It's better to call the manufacturer and ask."

When in doubt, call

Calling the unit's manufacturer or
the shop that did the original avionics
installation was a troubleshooting tip
shared by a lot of experts. It's a simple
Continued on page 36

avionics news

april

2015

http://beckerusa.com

Avionics News April 2015

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