400% increase in GPS Spoofing; Workgroup
established
OPSGROUP Team17 July, 2024

GPS Spoofing Risk changes, grows

900 flights a day on average are now encountering GPS Spoofing
Safety risks changing and growing: EGPWS primary concern
GPS Workgroup established to address issue

Troubling data shows a signiﬁcant spike in GPS Spooﬁng over the last few months, with an increasing
impact on ﬂight safety.
The number of ﬂights aﬀected has risen from an average of 200 daily in the period January-March, toaround 900 daily for the second quarter of 2024. On some days, as many as 1350 ﬂights have encounteredspooﬁng. Flight crews also report that the intensity of the spooﬁng is increasing.

Graph shows number of ﬂights aﬀected by spooﬁng, broken down by location. Data from Zurich Universityof Applied Sciences & SkAI Data Services.

At the same time, the number of locations where spooﬁng is highly active has increased from three tomore than ten. At the outbreak of the new spooﬁng phenomenon in September 2023, spooﬁng wasencountered in northern Iraq (near Baghdad), Egypt (near Cairo), and Israel. Since then, the Black Sea,Cyprus, the Korean border, and Russia have become spooﬁng hotspots.

Safety risk changing and growing
For ﬂight crews, the workload and knock-on safety risk resulting from spooﬁng encounters is both changing
and growing. Initially, the primary risk from a GPS spoof was navigational: autopilots began turning aircraft
unexpectedly, aircraft position became uncertain, IRS was sometimes lost. With ATC help, often throughradar vectors, the situation could be resolved.
With both the increase in intensity and frequency of spooﬁng this year, a second, more concerning set ofrisks is emerging.
The list is long. GPS is interwoven into many, if not most, aircraft systems these days. The EGPWS – ourtrusted friend to keep us away from terrain – is suﬀering heavily, and is becoming unreliable. False alerts –sometimes hours after the spooﬁng event – are now routine, and as a result, many are inhibiting thesystem. Crews are losing trust in what was until now an exceptionally reliable and critical device toeliminate CFIT accidents.
Go-arounds directly caused by GPS spooﬁng eﬀects are also being seen more regularly. False EGPWS
alerts are the primary culprit, but in some cases, the indicated wind on the Navigation Display is false andleads to confusion. In others, autopilot behaviour and unusual glideslope/localizer indications are causing
missed approaches. Any go-around immediately increases crew workload and reduces the safety margin.

Safety layer of “Swiss Cheese” removed
Other aircraft systems directly aﬀected include TCAS, ADS-B, HUD guidance, and transponders. The
aircraft clock, which crews are getting used to seeing “run backwards”, is often one of the ﬁrst victims of aspooﬁng encounter, and has knock-on eﬀects which include making CPDLC unusable. Eurocontrol report
now seeing this on a daily basis.
For Air Traﬃc Control, especially in Oceanic and remote regions requiring on-board responsibility fornavigation accuracy, life has thus become more challenging. Shanwick and Gander OACC’s now deal daily
with aircraft unable to meet the RNP4 requirement for oceanic crossings as a result of spooﬁng. Controllers
have to work harder to separate aircraft, and this has caused occasional diversions to Iceland.
The trouble is that these shifts in safety risk are happening without much attention to them. They arelargely unaddressed, latent pitfalls, that will become painfully clear when the ﬁrst accident attributable tospooﬁng occurs. A single, full layer of the “Swiss Cheese” has quietly been pulled out of our safety system
this year.

GPS Spoofing Workgroup established
A GPS Spooﬁng Workgroup has been hastily established to bring the international civil aviation community
together and address the problem. The Workgroup is now running, and will tackle the issue by collecting
data and information, surveying ﬂight crew, discussing the distinct elements of the problem, andproducing a community report. With the 14th ICAO Air Navigation Conference taking place at the end ofAugust, the timing of the ﬁnal report will aim to support discussions there.
450 participants have registered to take part in the Workgroup, which includes representatives of industry
organizations IFALPA, IFATCA, OPSGROUP, IBAC, EBAA, ECA, and BALPA. Airlines and Operatorsrepresented include Aer Lingus, Air Atlanta, Alaska Airlines, Cathay, Cargolux, Singapore Airlines, TurkishAirlines, United Airlines, Netjets, El Al, Royal Jordanian, Italian Air Force, USAF, American Airlines, LOTPolish Airlines, and Fedex.
An encouraging element of the Workgroup is the involvement of PNT and GPS experts from NASA, Boeing,
Collins Aerospace, FlightSafety International, Honeywell International, Safran Electronics & Defense,
Satcom Direct, Aircraft Performance Group, Fokker Services, Honda Aircraft Company, Zurich University ofApplied Sciences, and SkAI Data Services. Aviation Authorities participating include the Swedish CAA,Transport Canada Civil Aviation, Civil Aviation Authority of Singapore, Civil Aviation Authority of Thailand,
CAA Isle of Man, Eurocontrol, FAA, and NATS UK.
To date, the industry has largely focused on ad-hoc mitigation eﬀorts to deal with the GPS Spooﬁng
problem. The focus of the Workgroup will be to shift to discussing quickly available solutions, and broaden
industry awareness of the growing safety risks. It will also seek to provide Flight Crews with betterguidance, actions and GPS systems information.
The Workgroup is now complete. A ﬁnal report will be published on September 6, 2024.