Avionics News April 2022 - 48

ADS-B ADDS TO THE SAFETY TOOLKIT
Continued from page 47
available in the presence of an ADS-B Out broadcasting
aircraft, limiting the usefulness of purely ADS-B In
devices.
ADS-B In also requires a different, additional
capability in receiving aircraft, and general aviation
pilots started gobbling up ADS-B In equipment as
quickly as they came on the market - well ahead of
the ADS-B Out mandate date. As many pilots and
lobbyists pointed out in the run-up
to the mandate date, aside from
the weather (FIS-B) and traffic
(TIS-B), ADS-B was strictly a
benefit to the FAA.
ADS-B relies on two avionics
components aboard each aircraft:
a WAAS, TSO'd satellite
navigation source such as a GPS
or other certified GNSS receiver
and a datalink unit, typically a
Mode S transponder built to relay
the data via extended squitter.
There are many types of
certified ADS-B data links, but
the most common ones operate at
1090 MHz, essentially a modified
Mode S transponder, or at 978
MHz. The FAA would like to see aircraft that operate
exclusively below 18,000 feet (5,500 meters) use the
978 MHz link to help alleviate congestion of the 1090
MHz frequency. The 978 MHz band is what carries
the weather and traffic services.
To obtain ADS-B Out capability at 1090 MHz,
user-operators can install a new transponder or
modify an existing transponder if the manufacturer
offers an ADS-B upgrade (plus install a certified
GNSS position source if one is not already present).
To access the benefits of ADS-B In's graphic
traffic and weather tools, an aircraft needs a display
capable of showing the input, and many options exist.
For many pilots and operators, an electronic flight
48 avionics news * april 2022
WHILE MANY
THINGS WORTH
DOING ARE WORTH
DOING BADLY,
ADS-B ISN'T
A SUCCESS
DONE BADLY.
WITH ADS-B,
bag capable of receiving the ADS-B In transmissions
suffices. Other options include ADS-B In-capable
multifunction displays, many GPS navigators and
the primary flight display page of many integrated
avionics systems. Since ADS-B In is not required by
the FAA regulations, the choice is wide open.
Since the cost of ADS-B In capability comes at
a fraction of separate traffic and weather receivers,
the ADS-B In option enjoys great popularity among
operators and pilots flying older general aviation
aircraft for which those independent options cost a
large percentage of those aircraft's
market value.
It's difficult to rationalize $10,000
to $30,000 in new equipment for
aircraft with a market value under
$50,000, particularly for operators
who just had to drop several thousand
dollars meeting the FAA's ADS-B
Out mandate back on Jan. 1, 2020.
IT LOOKS LIKE
THE FAA GOT IT
JUST RIGHT.
Teething problems?
What teething problems?
A segment of the population has
a mindset that if the government is
involved in a project - particularly
one mandated for the public - expect
months, even years of ironing out its
problems. Delays and cost overruns
are the norm, such people believe. But there's
considerable evidence that the transition to ADS-B
for air-traffic surveillance and management came off
with uncharacteristic success, on time and on budget.
As the key technology underpinning the FAA's
next-gen air-traffic management plans, the FAA
spent years developing, testing and preparing for
the changeover from surveillance and air-traffic
management via ground-based radar to a space-based
service. But not without critics and complaints.
Critics developed their critiques years before the FAA
turned on the network. The biggest gripe? ADS-B offered
pilots nothing they couldn't get with other, non-mandated
hardware. ADS-B is for the convenience of the FAA.
Avionics News April 2022

Table of Contents for the Digital Edition of Avionics News April 2022
