“Terrain ahead. Pull up!”
It’s a command that ought to solely be heard in a catastrophe film or flight simulator. But pilots and aviation specialists say such warnings have been more and more sparking alarm in cockpits as bogus alerts from world positioning satellites hit business flights.
The disruption of GPS signals has turn into endemic in battle zones, together with the area now impacted by the Iran warfare, affecting planes on routes that skirt sizzling spots for army exercise in the Middle East, Baltic Sea and Black Sea. In instances of GPS interference, an airplane’s floor proximity warning system could lock onto a false sign, triggering unsettling warnings regardless that the aircraft is flying at a protected altitude.
“I have fellow pilots that encounter this on a regular basis. That’s the true danger. It’s becoming normalized,” mentioned Captain Ron Hay, president of the International Federation of Air Line Pilots’ Associations, which represents over 160,000 pilots in greater than 70 international locations. Hay, who works for Delta Air Lines, mentioned he feared that pilots would possibly lose belief in vital security programs as they turn into desensitized to those warnings.
In addition to harrowing phantom pull up instructions, flights encountering these spoofed alerts expertise irregular system responses equivalent to map shifts, the place the plane location on the cockpit display strikes miles from the precise flight path, or when a aircraft is on the runway prepared for takeoff, programs could erroneously counsel it’s elsewhere, in keeping with a 2026 useful resource information from the US Federal Aviation Administration.
Around 900 flights every day are affected by GPS interference, in keeping with Benoit Figuet, a analysis affiliate on the Zurich University of Applied Sciences and founding father of SkAI Data Services, which since 2024 has tracked such incidents on its web site GPSWise.
Cockpits are seeing their digital navigation shows “become a work of fiction” mentioned a business pilot, who didn’t wish to be recognized as a result of he was not permitted to talk publicly. He mentioned that pilots generally have to show off the “terrain inhibit switch” to silence alarms from floor proximity warning programs, manually decouple clocks from GPS and depend on ground-based programs “like it’s the 1970s.”
Pilots can use radar, inertial navigation instruments and navigate utilizing ground-based transmitters when GPS fails or turns into unreliable. But as a result of GPS is embedded in a number of programs on board an plane, spoofed alerts can movement by and have an effect on a number of totally different instruments equivalent to plane clocks, climate radar and passenger Wi-Fi. Ultimately the interference can result in flight disruptions and delays as confusion descends on the nerve middle of a aircraft.
Global Navigation Satellite Systems, or GNSS, equivalent to essentially the most extensively used US satellite-based system, GPS, are an intrinsic, if largely invisible, a part of the trendy world. With the flip of a change, GNSS permits for the calculation of exact location and the precise time, regardless of the place you’re.
But the alerts powering these programs — similar to the power of a few gentle bulbs — are straightforward to beat as a result of they weaken as they journey over 20,000 kilometers to achieve Earth from satellites in house. While this vulnerability has been lengthy understood, it began to turn into an issue for plane and ships after Russia’s invasion of Ukraine in 2022, throughout which drones have been extensively deployed in fight for the primary time.
GNSS interference includes militaries and affiliated teams deliberately broadcasting high-intensity radio alerts in the identical frequency bands utilized by navigation instruments. While the meant targets are sometimes drones and missiles, plane could be collateral harm. Jamming outcomes in the disruption of satellite-based positioning whereas spoofing results in navigation programs reporting a false location.
“The aircraft thinks that it is absolutely someplace else,” Hay mentioned. “The map doesn’t match. The time doesn’t match. There’s various cues that it’s going on but from what I’m told, the basic problem is when you’re being spoofed, you can determine you’re being spoofed, but you don’t know where you’re going to be spoofed.”
The matter was mentioned in a panel moderated by Hay at IFALPA’s annual convention in Istanbul on Thursday, he mentioned. Hay, who primarily flies Pacific routes, mentioned he had not personally encountered GPS spoofing or jamming.
Hay added that the difficulty is not one thing that passengers wanted to fret about from a security standpoint however slightly an operational headache for pilots, airways and air visitors management.
For instance, for plane headed throughout the Atlantic that encounter GNSS interference close to the Black Sea, Hay mentioned air visitors management would make sure that the automobiles are spaced a larger distance aside for security in case navigational reliability have been to be comprised. This may imply that an plane can’t use the North Atlantic observe system, a structured set of routes throughout the Atlantic that goals to accommodate as many plane as doable, which may end result in planes taking longer, much less fuel-efficient routes.
While most disruption occurs in the Middle East, Black Sea and Baltic areas, permitting flight crews on routes in these areas to anticipate potential points, Figuet mentioned SkAI Data Services had detected clusters in Asia, together with on the India-Pakistan border, round North Korea and South Korea, and Myanmar.
“There is risk, but I think it’s manageable risk, and what I don’t want to create is a false sense of panic,” he mentioned. “So, it’s an issue. It has to be fixed.”
Figuet mentioned the issues have largely to do with the extra burden positioned on pilots and the opportunity of delays or different logistical points. However, he mentioned that GPS interference has contributed to an aviation disaster: On December 25, 2024, an Azerbaijan Airlines flight touring from Baku, Azerbaijan, to Grozny, Russia, crashed in Kazakhstan.
According to a February 2025 preliminary report by Kazakhstan’s Ministry of Transport that included voice logs, the pilots encountered electronic interference. They misplaced GPS and reported “pull up” warnings close to Grozny, the place fog made touchdown utilizing beacons troublesome.
After two unsuccessful touchdown makes an attempt on the Grozny airport, the pilots determined to return to Baku. At some level in the course of the return, the plane misplaced its main management programs, and the crew tried to make an emergency touchdown, the report famous. At least 38 of the 67 folks on board the aircraft have been killed.
In October 2025, Russian President Vladimir Putin mentioned missiles fired by Russian air defenses to focus on a Ukrainian drone that exploded close to the plane had been accountable for the jet crash.
“GPS interference was not the primary cause of the crash. But because of GPS interference, they could not land where they were supposed to,” Figuet mentioned.
Ramsey Faragher, chief government of the Royal Institute of Navigation in London, agreed. “If it hadn’t had the problems with its GNSS, it would have very, very, very likely landed an hour earlier,” he mentioned of the Azerbaijan Airlines flight. Faragher additionally took half in the panel dialogue on the IFALPA convention final week.
Pilots are well-trained to handle GNSS interference, a phenomenon that Aleksi Kuosmanen, chief flight teacher and captain at Finnair, described as a each day nuisance.
Most flights that depart southbound from Helsinki encounter GPS spoofing and jamming, Kuosmanen mentioned. A Finnair flight on April 6 that was carrying passengers to Kirkenes — a city in northern Norway near the Russian border, the place vacationers go to identify the Northern Lights — needed to make a second touchdown try after encountering GPS interference on the primary strive.
“The effect on pilots, whether it be jamming or spoofing, is probably increased workload in the cockpit and concentrating on this spoofing takes, of course, a fair amount of your mental resource,” he mentioned.
Finland’s Transport and Communications Agency Traficom mentioned it had obtained 421 reviews of GPS reception interference in January and February this yr. Last yr, it mentioned it obtained a complete of 1,704 reviews.
Finnair, which flies round 100,000 flights a yr, additionally suspended flights to Tartu in Estonia for a month in 2024 whereas the airport there made enhancements to its ground-based touchdown programs that pilots depend on in the event that they encounter GNSS interference.
“We’re in a position to manage the situation, and the pilots are used to it. But I wouldn’t like to see this as a new normal, that we are continuing many, many years from now with this kind of situation so our stand is to state that this is not acceptable,” he added.
The FAA mentioned in its report that as GNSS interference turns into extra frequent, organizations and pilots could develop a better tolerance for danger. “GNSS interference can lead to mistrust in flight deck systems when the technology’s validity, reliability, or robustness is compromised,” the FAA report famous. “Once trust in these systems is lost, it can be difficult to regain. This mistrust may ultimately impact how flightcrews utilize information and respond to alerts.”
Finland was amongst 13 European Union members that shared an open letter in June final yr calling for motion on the difficulty, which resulted in a European Aviation Action Plan revealed in March. It consists of proposals for short-term actions equivalent to growing customary phrasing when speaking with air visitors management and longer-term targets of coordinating with army businesses to acquire well timed data on sources of GNSS.
Faragher mentioned that dwell jamming and spoofing consciousness maps equivalent to these supplied by SkAI Data Services can already be built-in into electronic flight luggage, the digital data administration system utilized by crews. This software program may give pilots a clearer indication of the place to anticipate interference and thus make it simpler to keep away from. IFALPA recommends a floor reset after each flight suspected to have been influenced by GNSS interference to erase corrupted GNSS alerts from all programs.
Beyond these first steps, adjustments to cockpit avionics may assist higher handle the issue by bettering software program filters that detect massive jumps in place and time, and ensuring floor place warning programs don’t retain spoofed data, Faragher mentioned. Longer time period, adjustments in plane system design to allow the isolation of the GPS receiver from all different plane programs would additionally assist, he added.
“It is disappointing that the hardware manufacturers have not fixed some of these problems by now,” Faragher mentioned. “Given the right motivation, things can happen much more quickly, and we need to figure out how to get the sort of right motivations going.” He identified that when terrorists stormed cockpits on 9/11, locks have been put in on cockpit doorways “within weeks.”
Airlines have additionally been investigating the set up of Controlled Reception Pattern Antenna, which have a capability to filter out spoofing alerts, he mentioned, and Galileo, the European GNSS, now has a characteristic that permits customers to authenticate the info they obtain.
Companies and governments are additionally exploring whether or not stronger satellite tv for pc alerts despatched from low Earth orbit may improve GNSS navigation in addition to planning enhancements to GPS satellites presently in medium Earth orbit. The European Space Agency’s Celeste mission transmitted its first navigation signal on April 17. The mission goals to launch a complete of 11 satellites that may fly in low Earth orbit to check alerts throughout varied frequency bands in order to enhance positioning and navigation.
“We are in a phase of waiting — waiting for new technology, and in the airline industry the change isn’t always that fast,” Kuosmanen mentioned.
“New equipment, new system software requires a lot of testing before they can be set up,” he added. “In the meantime, it’s our job to make sure that our pilots are trained to competently handle these situations.”
NCS’s Katharina Krebs contributed to this report.