The incident occurred on 30/6 aboard LOT Polish Airlines flight LO155, which was en route from Warsaw, Poland, to Tel Aviv, Israel. The aircraft involved was an Airbus A320 operated by Electra Airways, carrying about 180 people.

LOT Polish Airlines stated the aircraft activated transponder code "7500". This code allows pilots to secretly inform air traffic control about an "unlawful interference" situation, an aviation term for a plane under hijack.

Bulgarian security forces inspect the Airbus A320 after the 30/6 incident. *Business Insider*

Activating the "7500" code prompts air traffic control to immediately clear airspace around the aircraft and initiate emergency response procedures, including notifying the military to deploy fighter jets for monitoring.

The alert was later canceled when the flight crew contacted air traffic control.

Clash Report, an X account specializing in tracking conflict information, stated that a Bulgarian MiG-29 fighter jet approached the plane and closely tracked it within Bulgarian airspace. Two Turkish F-16 fighter jets then took off to monitor the A320 throughout its flight over Turkish territory. Israel also dispatched two fighter aircraft to patrol over the Mediterranean Sea.

Flight tracking data showed the A320 changing its route, circling in the eastern Mediterranean near Cyprus, before diverting and landing in Burgas, Bulgaria, that same afternoon.

A Bulgarian MiG-29 fighter jet practices intercepting a target during a NATO exercise in 3/2025. *USAF*

Upon landing, all passengers disembarked for inspection by Bulgarian security forces.

LOT Polish Airlines issued an apology to passengers, explaining the diversion was due to "unintended activation of an onboard security alert" and emphasized that this was an "extremely rare" situation. However, the airline did not specify if the 7500 code activation resulted from human error or a transponder malfunction.

By Thanh Danh (Sources: Times of Israel, Business Insider, TWT)