Avionics News November 2015 - 73
THE VIEW FROM WASHINGTON
Continued from page 11
Finally, if you already have a Mode S transponder that is in
good working order and is upgradable to be ADS-B compliant
(not all of the early models are), then upgrading your current
equipment would likely be the most cost-effective option.
I don't want to minimize the potential benefit of the universal access transceiver (TSO-C154c) ADS-B equipment operating on the frequency of 978 MHz. Assuming the operator
doesn't have the need to fly in Class A airspace, international
airspace, or have other regulatory needs, the UAT solution
may make perfect sense. One benefit of UAT is that many of
the UAT systems allow for both ADS-B Out transmitter as
well as a self-contained WAAS receiver - a single, self-contained ADS-B Out product. In some cases, the UAT systems
may also contain an ADS-B In receiver providing safetyenhancing weather and traffic information into the cockpit.
The UAT solution is a common solution for light general
aviation aircraft both from a functionality perspective as well
as a value perspective.
The position source
The next element of ADS-B is the position source. With a
focus on WAAS, there are a few different methods of achieving a satisfactory result. The internal navigations system
can provide an acceptable output, or a stand-alone WAAS
received either attached to or imbedded in the transmitter can
satisfy the requirements.
This comes down to how you fly: IFR or VFR? Do you rely
on ground-based navigation sources or space-based sources?
If you fly VFR, then you likely would benefit from one
of the ADS-B systems with either an imbedded WAAS or a
bolt-on WAAS for ADS-B only. This is especially reasonable
should you already have a GPS providing point-to-point (en
On the other hand, should you fly IFR, then you should evaluate your navigation system for upgrade, as well. While there
is no direct mandate for navigation updates on the regulatory
radar, the FAA and authorities worldwide are supplementing
and, in many cases, replacing ground-based navigation systems.
Most aircraft have at least a GPS system installed. But how old
is it, and how well is it supported by the original manufacturer?
Many of the early GPS systems are no longer supported by the
OEM, and in many cases, the OEM is not even in business any
longer. Perhaps your flying style has modernized and you find
yourself wanting more capability than your legacy system is
offering; you want to fly LPV, PRNAV, etc. These are all good
reasons to evaluate your current navigation equipment and use
the ADS-B Out installation as the springboard to upgrade your
navigations system, as well.
According to Gary Harpster, avionics installations sales
representative at Duncan Aviation, "When discussing
ADS-B for the international business aircraft, first hit upon
the key word international. With that factor as part of the
equation, the operator knows they need to get their aircraft
compliant for international travel, and that involves a higher
degree of accuracy from the GPS receivers
(WAAS), which means they have already covered a big portion of the expense for the ADS-B
solution. For an aircraft that already has WAAS,
generally speaking, they need a transponder
upgrade, cockpit annunciation and, of course, the
The third consideration is time. Based on a
survey conducted by the AEA, the installation
time for ADS-B Out systems can vary dramatically. For light general aviation aircraft, the
average installation time is approximately 20
hours, with the more complex systems taking 80 to 100
hours. In the large business aircraft, again depending what
systems are already installed and what systems need to be
upgraded, the installations can take as long as four weeks,
while the overall average is closer to 55 to 60 hours.
Time is a consideration because the larger the aircraft,
the more time it takes to perform the installations and
upgrades and the fewer service providers that are available. Overall, regardless if you operate a small recreational aircraft or a large international business jet, the best
advice we can share comes down to this: Talk to your
avionics provider; plan your upgrade; and most important,
schedule your installation.
With little more than 1,000 days left, there isn't much