Avionics News October 2015 - 36

STC GIVE AND TAKE

Finding test aircraft is not a problem, Rankin said. Peregrine's home is
Colorado's Centennial Airport. With its
"vibrant GA activity, it's not too hard to
find aircraft owners interested in partnering with us in STC efforts." Peregrine
searches for airframes with the necessary mix of avionics that the STC will
upgrade. "For Trig, we started with a
legacy airplane with a KT 76 Mode C
transponder and no GPS and said what
would someone do for ADS-B Out in
this situation, and we'd install a TT31
and GPS/WAAS position source."
Peregrine is not a Part 145 repair station, Rankin noted. "We work with local
avionics shops," he said. "Arapahoe
Aero Avionics is just down the street

36

avionics news

*

october

2015

Photo courtesy of Peregrine

Continued from page 35

from us, and they do all the work on
Part 23 aircraft. Duncan Aviation does
the work on Part 25 aircraft." Most of
the STC test aircraft are ready for an
upgrade, "and in many cases we can
reach out to owners who are bringing
their aircraft into the shop anyway."
Many owners of the test aircraft "work
out an arrangement to keep the equipment."
The entire STC cycle takes about six
months, and the timeline depends on the

The Cessna 310 is
among the hundreds
of aircraft on the
approved model
list for the remotemounted Trig TT22
ADS-B STC.

specific components in the installation. It
begins with a review of the technical data
for each component, which can involve a
lot of back and forth conversations with
Trig. Many of the critical performance
requirements are specific to the component's architecture and software. Trig
provides that information, and when necessary, Trig has tweaked them to achieve
the required system performance. These
are minor changes that provide a compatible interface and don't affect the
transponder's overall certification, Davis
added. But this is not a simple process,
because avionics today employ a number
of different interfaces, "and we have to
make sure the tweak hasn't resulted in
an unexpected change in another aspect
of the unit."
Most of the time invested in the STC
is deskwork and documentation, Rankin
said. Following the FAA-approved test
plan, once Peregrine completes the engineering deskwork and documentation, it
evaluates the installation on the ground
with special test equipment. With this
step successfully completed and documented, "we get to fly."
The two-hour test flight in the local
area is coordinated with the FAA in
advance. "We tell them what we are
going to do and request a comprehensive data report that includes all of the
key parameters of GPS location, velocity and altitude," Rankin said. The flight
includes all the standard maneuvers in
a flight from start to finish. After the
test flight, it's back to the desk, where
the engineers compare the ADS-B data
recorded by the test equipment on the
aircraft with the data received by ATC.
http://www.capitalavionics.com
Table of Contents for the Digital Edition of Avionics News October 2015
