AOPA Turbine Pilot Magazine - July 2022 - T-19

Opposite page: The southern " Blue Spruce "
routes, popular with jets without the range to
cross the Atlantic nonstop, fall in the datalink
mandate airspace. This leaves aircraft without
FANS two options: route farther north through
the exempt airspace, or fly outside the
vertical limits of the mandate. Above: Reading
clearances removes ambiguity because of
poor radio reception, frequency congestion,
and accents of non-native speakers.
communication medium is one also used
by ACARS and FANS-the VDL radio.
ATN: WHAT DO I NEED?
Only software and hardware. As equipage
is partially mandatory over Europe
(more on that later), the network costs
are born by ATC, and no subscription is
required. You will need the software, and
again, unless it comes standard for your
aircraft, it will be an additional cost above
and beyond the ACARS and/or FANS
" apps " you may have purchased. You will
also need the third VDL radio option (no
satellite data transmission allowed as it's
too slow), but that same radio can also be
used for ACARS and/or FANS interfacing.
ATN: WHERE IS IT REQUIRED?
In short, over Europe when flying above
FL285. The program suffered extensive
delays, however, which resulted in some
generous exemptions being handed out.
If an airplane has under 20 seats, and a
maximum takeoff weight below 100,001
pounds, and was granted an airworthiness
certificate before February 5, 2020,
the exemption is (for now) permanent.
For any new aircraft put into service,
however, equipage is mandatory for flight
over FL285.
ATN: WHAT WENT WRONG?
In short, a lot, but the full extent is still
being identified. As the system became
operational, but before the mandate was
in place, a high level of " provider aborts, "
or dropped connections, were experienced-leading
to lost or timed-out
messages, even for aircraft not experiencing
connection problems. Several
control areas reacted by banning all logons
unless an aircraft could prove their
avionics platform could demonstrate
an acceptable abort rate. This " white
list " became the current " logon list, "
and requires an operator to complete
an online form identifying their hardware
and software configuration before
being allowed to log on to ATN in several
of the busiest blocks of European
airspace. Once admitted to the logon list
connection performance is monitored,
and aircraft may find themselves kicked
off should they experience a higher abort
rate than other aircraft operating in the
same area.
Eurocontrol points fingers at avionics
software, while avionics manufactures
are quick to point out that ground-side
changes have been required to increase
the performance of the system, and that
the system is far more congested at altitude
than ideal, with up to 60 ground
stations being heard by a single aircraft.
It's important to note the distinction
between the mandate and the logon list-
an aircraft may be required to have ATN
to fly above FL285, while simultaneously
be prohibited from using ATN in designated
control areas until its software is
updated.
AOPA PILOT / July 2022
T-19
AOPA Turbine Pilot Magazine - July 2022

Table of Contents for the Digital Edition of AOPA Turbine Pilot Magazine - July 2022
