A twin-engined aircraft with its transponder switched off flew over seven European countries. Accompanied by fighter jets, it landed in Bulgaria: police found no one on board.

Lithuanian news broadcaster LRT on June 10, 2022, the unidentified plane appeared to be a Piper PA-23–250-Aztec twin-engined light aircraft, which was previously registered as LY-LOO.  Its manufacturer’s serial number is 27-2250. The aircraft was misidentified as a Beechcraft in earlier reports published by Romanian and Hungarian media. 

For a whole day, the aircraft flew over the skies of Eastern Europe, but it did not communicate with any control tower or interfaced with their radars. The ghost plane that took off from Lithuania on June 8 with two Russian-speaking individuals on board, remains an unsolved mystery. It crossed seven NATO countries and landed in Bulgaria, escorted – but not shot down – by Hungarian and Romanian military fighters and never responded to any signals. There were no passengers on board once it landed in Sofia. When the Bulgarian police checked the aircraft, the engine still hot.

The Piper twin-engined phantom plane

The phantom aircraft was a twin-engined, six-seater Piper PA-23–250-Aztec. The small aircraft had belonged to the director of Nida Airfield, Bronius Zaromskis, who claims to have sold it very quickly to an unidentified Russian-speaking customer during the last week in Panevezys, northern Lithuania.  

Zaromskis told local media that the three men who arrived to inspect the plane before purchase were not Lithuania nationals. 

“I cannot guess which country they were from. They might be Ukrainians, maybe Romanians or Bulgarians. I was speaking to one of them in the Russian language. But I don’t know the names of any of these men, I was not interested,” the plane’s former owner was cited as saying by LRT.  

He added: “I’ve been trying to sell that plane for years, I had nowhere to store it, so I’m glad somebody bought it. I don’t remember the name of the company which bought it.” 

The Nida airfield is not far from the Russian base of Kaliningrad (an enclave of Russian territory in the middle of Europe), he told the press. The payment was made through a convenient company, making the real buyers untraceable.

The pirate plane’s flight route took it over 7 European states

After the purchase, there are few traces available in this story. It is certain that the plane took off from Lithuania on June 8, with two Russian-speaking passengers on board.

Speaking to Lithuanian media, Oro Navigacija, a local state-owned company that provides air traffic, communication, navigation, and surveillance services in the region, said it does not have any data related to the flight, although it reportedly took-off from Lithuania on June 8, 2022. 

However, it is thought that the plane did not take-off from any of the three main civil Lithuanian airports – Vilnius (VNO), Kaunas (KUN), or Palanga (PLQ). Instead, it could have left the country via any one of the country’s minor airfields.

The first unauthorised landing and chase in Hungary

Flying low and with all signalling systems off, the Piper escaped control systems, flew over Poland and reappeared on radar in Slovakia and Hungary. According to Hungarian press, the aircraft entered Hungarian airspace from Slovakia and in the afternoon landed at Hajdúszoboszló Airport without permission.

The pilot then threatened an airport worker who called the police. When the police arrived and approached the plane, the pilot “gave it full throttle and took off” at around 17:30 hrs., violating all flight rules, according to a report by Rtl.hu. 

According to the Romanian Ministry of National Defence, the plane had no confirmed flight plan and did not respond to any attempts to establish radio communication, and ignored all visual signals. However, it “did not show hostile or dangerous behaviour”. 

Then, a pair of Hungarian Air Force Saab JAS 39 Gripen fighter jets chased it: attempts to get in touch with the crew were in vain, the plane did not respond. From the base of Feteşti, US fighter jets also take flight, then Romanian ones.

The military planes escort the mysterious flight, but the phantom aircraft’s transponder remains off and there will be no way to get in touch with its two passengers on board.

Bulgarian media reported that at around 17.49 CET the plane entered Romanian airspace in the vicinity of Oradea. As per a cross-border agreement between Romania and Hungary, the Hungarian jets continued to accompany the mystery plane. Several minutes later, it was intercepted by two patrolling US Air Force F-16 Fighting Falcons from 86th Feteşti Air Base. 

At around 18:36 CET, the surveillance was taken over by two Romanian Air Force F-16s. While being followed, the aircraft entered Serbian airspace for two minutes in an area between Drobeta-Turnu Severin and Korbovo.  

The plane is then seen again over Serbia and then at 19:09 hrs in Bulgaria. No Bulgarian Air Force fighter jets were scrambled and no alarm was raised.

“At no time the plane was a threat to the civilian or military infrastructure of Bulgaria. It was flying at a low altitude, difficult to catch by fighters, but we monitored it at all times. We located where it landed and are working to establish the circumstances,” Bulgarian Minister of Defense Dragomir Zakov told Bulgarian media on June 9, 2022. 

In Targovishte, Bulgaria, the plane lands on an unused runway at Buhovți Airport, a small airport. But when the police arrive it’s too late. The engine is still hot, but no one is on board: the two pilots had disappeared. The plane was reportedly found covered with a tarpaulin with no signs of any crew or passengers.  

The Prosecutor’s Office of Bulgaria has opened an investigation to locate the pilot of the plane.

Provocation or test against NATO?

The secret services from all over Europe are working to understand what happened and the identity of the two pilots. Security experts say that it is very strange that military aircraft did not act against the aircraft, which was able to fly through the skies of 7 seemingly undisturbed European countries, right now that the alert is high due to the war. The mystery remains about the reasons for the flight: some have already speculated that it was a Russian test to assess security measures, responsiveness and the “penetrability” of the skies over NATO member countries.

Parts of European airspace have become more challenging recently. Besides the usual summer ramp-up of operations, airlines also have to keep a watchful eye on events in Ukraine. Possible GPS interference or spoofing can affect operations. There are many more risks, that EASA, Europe’s aviation safety watchdog, has analysed thoroughly in previous months.