AOPA Turbine Pilot Magazine - March 2025 - T-4

We departed Quebec City, Canada,
for a fast crossing through Greenland
and Iceland before enjoying three days
in Prague, Czech Republic. We wandered
on foot through charming cobblestone
streets, making our way to Prague Castle
amid the stunning architecture of the
city. After a relaxing stay at a private
olive-farm villa turned boutique hotel
on the Adriatic Sea in Croatia, we flew
over Turkey on our way to our next destination:
Tbilisi, Georgia.
Our flight through Turkey and over
the Black Sea was one of the most interesting
experiences we have had as pilots.
This region is known for frequent GPS
jamming and spoofing (possibly due to
geopolitical reasons). We were wellprepared
and briefed on the likelihood
of encountering these issues during our
flight. Nonetheless, the first time you
experience GPS jamming for hundreds of
miles in a foreign country, with Ukraine
to the north and Iran to the south, makes
for a high stakes and unforgettable flight.
The first hint is a yellow crew alerting
system message saying " ADS-B OUT
FAIL " (as ADS-B needs GPS to transmit
T-4
AOPA PILOT / March 2025
the position); then you get a " GPS NOT
USED " message on the primary flight
display when the Garmin G3000 is using
DME/DME for positioning. Once you
lose GPS and DME/DME is not available,
you get other CAS messages such as
" TERRAIN FAIL " and " UNABLE RNP, "
and all the numbers and information that
are normally magenta become yellow.
One even more interesting data point
was the wind display on the PFD-it
showed a crosswind of 242 knots in yellow.
A quick scroll to the GPS status page
shows " GPS NOT READY " and no satellite
displayed on the satellite report page.
Seeing " DR " for " dead reckoning "
in the middle of each screen quickly
became the new normal during this
flight. As a pilot, while looking at the
map, you tell yourself, As long as we
maintain a heading of 090, we should be
good to go. All jokes aside, we had prepared
as thoroughly as possible. We took
extra steps, coordinating with the supervisor
of Turkey's Ankara Control Center
to ensure constant radar coverage in case
vectors were needed en route. We also
reached out to Tbilisi Control to ensure
a smooth handoff between Turkish and
Georgian airspace.
With thousands of flights over Turkey
daily and the frequent GPS jamming and
spoofing, controllers are adept at handling
these situations. When you report
a " loss of GPS capability " to ATC, they
ask if you would like vectors. While the
obvious answer is yes, controllers ask
because larger, long-range aircraft are
equipped with inertial navigation systems
(INS). INS uses accelerometers and
gyroscopes to determine the aircraft's
position, velocity, and orientation without
relying on external signals like GPS.
This system provides accurate navigation
information and is especially useful when
GPS signals are unreliable or unavailable.
Unfortunately, Citations and Phenoms do
not have an INS system onboard.
Before this flight, we practiced tracking
inbound and outbound VOR radials
to stay on the airways. We were also
equipped with iPad satellite receivers that
can connect to the GLONASS Russian satellite
system, which are less susceptible
to jamming and spoofing. Additionally,
in preparation for the trip, we consulted
AOPA Turbine Pilot Magazine - March 2025

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