The night before Saturday, a Finnair plane was forced to turn back to Helsinki after GPS disturbances kept it from landing in Tartu.

Kukemelk said that GPS signals are being disrupted from Russia.

"It is likely there are signals the Russians are trying to scramble, and vice versa, radars are being used to map troop movements. Unfortunately, the Tartu Airport has been affected as it is the closest regional airport to Russia. These efforts are not unilateral, with both sides trying to collect as much information as possible on the other's movement and activities," the expert said, adding that the Kuressaare and Kärdla airports in Western Estonia have not had similar problems.

"Russia has no interest in keeping flights out of Tartu, that is not what this is about at all. But Southern Estonia is home to the Kuperjanov Battalion, and they very much want to know troops from which countries and what kind of military equipment is hosted there. Just as I'm convinced that NATO wants to know what is happening near Pskov, what types of planes are kept there, how many troops etc. These GPS disturbances are a side-effect of that."

EDF: We are not suppressing GPS signals

But representatives of the Estonian Defense Forces (EDF) told ERR that Kukemelk is merely speculating as concerns the armed forces and creating a false impression of the situation.

"I can assure you that the EDF is in no way connected to these GPS disturbances – the EDF is not scrambling or suppressing GPS signals," said Lt. Martin Hiir from the EDF Headquarters.

Air traffic control should return to Tartu

Such disturbances do not phase major airports like the ones in Tallinn or Riga because they have ILS systems and operate a controlled airspace. But Tartu Airport switched to a remote tower system for economic reasons in 2022, which is why it can only inform flights instead of offering flight control services.

"In other words, we are talking about uncontrolled airspace where a pilot has access to information but has to decide whether to land or not themselves. Without a proper GPS signal, landing is made more difficult, whereas the pilot is the one responsible. If Tartu still had air traffic control and an operational ILS beacon, we would not have the problem today," Kukemelk said.

The expert said that while he is aware of plans to equip the airfield in Tartu with a DME radar by year's end, a faster, possibly temporary solution is needed if Finnair is to continue flying to the Southern Estonian city.

"Finnair will not be able to continue these flights if a solution is not found. To an extent, this matter is in the hands of the Estonian Air Navigation Services and the Transport Administration. Whether they want to restore air traffic control at Tartu Airport. Provided the will is there, it could be done quite quickly," the aviation expert opined.

He added that while restoring air traffic control at Tartu would not make economic sense, the same could be said of the Helsinki-Tartu air link, which is receiving state subsidies.

"It is a matter of political choices. The link is crucial for the Tartu area and Finnair is interested because demand seems to be there. You do not compromise when it comes to aviation safety," Kukemelk explained.

The reason why the two Finnair flights that could not land in Tartu returned to Helsinki and not Tallinn was logistical and aimed at avoiding schedule disruptions, the expert also said.

Ministry secretary: Air traffic control in Tartu needs to be restored

Efforts to scramble GPS signals from Russia are sure to continue, meaning that unless Finnair amends its flight safety protocols, changes will have to be made at Tartu Airport for flights to continue, said Keit Kasemets, secretary general of the Ministry of Climate.

"The Estonian Air Navigation Services has developed a DME (Distance Measuring Equipment) navigation network, which offers an alternative to GPS-based guidance, while this does not happen automatically. Air traffic control services at Tartu Airport should definitely be restored. We are working with the Transport Administration and the navigation service to find the fastest and most effective way to do that. Technically, Tartu Airport is ready to restore air traffic control today," Kasemets said.

"Settling for flight disruptions because of Russia's hostile actions is not a good solution, and we will try to avoid it if at all possible," he added.

Mayor: We want a reliable flights schedule

Mihkel Haug, in charge of air traffic control at the Estonian Air Navigation Services, said that because the situation is novel, he cannot speak to detailed solutions yet.

"We are looking for the fastest solutions, and we'll have working groups on it from Monday. The general guideline from the EU and the aviation sector in general is to switch to GPS guidance. We may have to reevaluate that in the current situation," he noted.

Tartu Mayor Urmas Klaas said that the city wants the Helsinki flights to continue on schedule.

"There are no grounds in the current situation to reduce or withhold the subsidy. Our motivation is keeping the agreed-upon schedule," Klaas said.

Minister of Foreign Affairs Margus Tsahkna (Eesti 200) said that disrupting air traffic amounts to a hybrid attack and that he plans to broach the subject with allies.

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