A LOT Polish Airlines flight from Warsaw to Tel Aviv accidentally broadcast the international hijacking signal over Bulgaria on Tuesday, prompting fighter jet scrambles by three air forces before landing safely on the Black Sea coast. The Airbus A320, operated by Bulgaria’s Electra Airways, transmitted transponder code 7500 while in Bulgarian airspace, the silent squawk pilots are taught to use when an aircraft is being seized. Bulgaria’s transport ministry blamed a technical failure of the aircraft’s transponder; an airport official earlier told reporters the Bulgarian operator blamed pilot error.
The Israeli Air Force scrambled two fighter jets over the eastern Mediterranean. Türkiye sent two F-16s to escort the jet through its airspace. The aircraft was denied clearance to land in Israel near Cyprus because the alert remained active, and LOT Polish Airlines spokesman Krzysztof Moczulski told AFP the diversion to Burgas Airport was “due to limitations related to the authorized working time for the crew.”
What Squawk 7500 Is Designed to Do
Transponder code 7500 is the internationally agreed signal for unlawful interference, set aside so a pilot under duress can alert air traffic control without tipping off a hijacker. The pilot either confirms the squawk when ATC asks or stays silent; per ICAO procedures mirrored in national aeronautical information publications, silence is treated as confirmation of the threat. The code sits apart from 7600 (radio failure) and 7700 (general emergency) so controllers can read the nature of the problem at a glance.
Qatar’s Aeronautical Information Publication lays out the procedure for code 7500: “the pilot of an aircraft in flight which is subjected to unlawful interference shall endeavour to set his transponder to Code 7500.” The next paragraph notes that if ATC asks the pilot to confirm, the pilot either confirms or does not reply at all, and the absence of any reply is taken as confirmation of the threat.
That design, built for speed and discretion, is exactly why a false 7500 from a faulty transponder box can mobilise the same military assets a real hijack would. The crew told controllers there was nothing abnormal on board; the false code kept drawing interceptors until the aircraft was on the ground.
Three Air Forces, One False Signal
Bulgaria scrambled a MiG-29 to intercept the airliner and escort it through Bulgarian airspace, the country’s transport ministry said. The jet took off the moment code 7500 lit up on radar screens in Sofia.
Israel’s military launched two fighter jets toward the civilian aircraft over the Mediterranean after what it called “a report of lost communication.” The IDF said in a statement that “two Israeli Air Force fighter jets were scrambled a short time ago toward a civilian aircraft over the Mediterranean Sea following a report that contact with the aircraft had been lost,” adding that the incident had ended and “there is no concern of a security-related event.”
Türkiye’s Transport and Infrastructure Ministry said two F-16s escorted the aircraft from the moment it entered Turkish airspace until it exited. The F-16s took the jet up again on its second pass through Turkish airspace, this time headed for Burgas, before the aircraft touched down safely at 5:12 pm local time.
Israel’s brief refusal to let the jet land near Cyprus, while the 7500 squawk was still active, forced the diversion that ended at Burgas. Once on the ground, the airline cancelled the emergency in subsequent communications with air traffic control.
- LOT Polish Airlines Flight 155 departs Warsaw Chopin for Tel Aviv, operated on an Airbus A320 by Bulgaria’s Electra Airways under a wet-lease.
- Aircraft broadcasts transponder code 7500 over Bulgarian airspace, the international signal for unlawful interference or hijacking.
- Bulgarian Air Force scrambles a MiG-29 to intercept and escort the airliner.
- Aircraft enters Turkish airspace; two Turkish F-16s take up escort from the border.
- Israeli Air Force scrambles two fighter jets over the eastern Mediterranean after reports of lost contact.
- Flight denied landing clearance near Cyprus while the alert remains active.
- Aircraft exits Turkish airspace, then briefly re-enters en route to Burgas on the Black Sea coast.
- Aircraft lands safely at Burgas Airport at 5:12 pm local time.
Pilot Error or Technical Fault, Two Stories in One Day
An airport official told AFP on Tuesday that the Bulgarian operator blamed pilot error. Warsaw Chopin airport spokesperson Piotr Rudzki went further, telling the agency: “We have no reason to take action in this situation. The (Bulgarian) airline is reporting pilot error, so no action is required on our part. We are monitoring the situation; nothing indicates any (external) interference.”
“The reason for the diversion is a technical failure of the aircraft’s transponder, which transmitted a false signal of unlawful interference/hijacking.”
Bulgaria’s transport ministry added that “after confirmation that there was no real threat on board, the aircraft left the country’s airspace via Turkey.” The ministry’s statement superseded the pilot-error account hours after it surfaced, with the transponder explanation taking the official line.
Türkiye’s transport ministry said LOT Polish Airlines had initially attributed the signal to pilot error, then watched Bulgaria’s transponder-failure explanation replace it within a day. The two narratives, swapped out in the same news cycle, show how a single transponder hiccup can produce parallel origin stories before investigators settle the cause.
Why the Diversion Went to Burgas
Burgas is where Electra Airways is headquartered, so the crew and the maintenance base were already there when the diversion order came down. LOT Polish Airlines spokesman Krzysztof Moczulski told AFP the rerouting was “due to limitations related to the authorized working time for the crew.”
Bulgaria’s transport ministry said the aircraft exited Bulgarian airspace via Türkiye at the operator’s request, then returned to Burgas for the landing. Israel denied the aircraft clearance to land near Cyprus because the alert remained active, leaving Burgas as the only practical destination inside the duty-time window.
The Wet-Lease Behind LOT’s Daily Warsaw-Tel Aviv Service
The Warsaw-Tel Aviv service runs on a wet-lease, also called an ACMI lease, between LOT Polish Airlines and Bulgaria’s Electra Airways, in place since October 2025. Under the deal, Electra supplies the aircraft, crew, maintenance, and insurance, while LOT sells the tickets under its own code.
According to ch-aviation’s report on the wet-lease terms for the Warsaw-Tel Aviv service, the leased Airbus A320-200 carries registration LZ-EAH and is a 19.1-year-old aircraft first delivered to Air Arabia in 2006. The jet is parked overnight in Tel Aviv and operates the Warsaw-Tel Aviv-Warsaw service daily.
LOT suspended its earlier contract with Hello Jets in May before adding the Electra A320. The cooperation was planned to continue throughout the 2026 summer season. LOT’s in-house narrowbody fleet is an all-Boeing list of eighteen B737-8s and six B737-800s, and LZ-EAH is currently its only wet-leased narrowbody.
The Warsaw-Tel Aviv route has had repeated suspensions tied to regional security conditions. LOT was among the first carriers to return to the airport after the 2024 Israel-Lebanon ceasefire, a backdrop that has shaped other carriers’ return schedules to Ben Gurion.
A Pattern of False 7500s
This is not the first false 7500 to mobilise fighter jets over Israel. In February 2026, jets were scrambled to escort a Wizz Air flight to Tel Aviv from London Luton after what the IDF called a “threatening message” on a passenger’s phone. The jets escorted the aircraft back to the airport, “and it was found that there was no real incident,” according to the IDF.
Aviation forums document pilots accidentally selecting code 7500 when they meant to select 7600 (radio failure) or 7700 (general emergency), since the three numbers sit adjacent on cockpit transponder panels. In other cases, faulty transponder hardware has broadcast 7500 on its own, the exact scenario Bulgaria’s transport ministry cited on Tuesday.
Bulgarian authorities blamed the false signal on transponder hardware, not pilot confusion. That puts Tuesday’s incident in a narrower bucket, hardware fault, but the operational result, three air forces scrambled, was the same.
Frequently Asked Questions
What is transponder code 7500?
Code 7500 is the international transponder squawk reserved for unlawful interference, including hijackings. The procedure is laid out in ICAO guidance mirrored in each country’s aeronautical information publications, with pilots setting the code so ATC can be alerted without notifying anyone in the cockpit. The pilot then either confirms when ATC asks or stays silent; silence is read as confirmation.
What flight was involved?
LOT Polish Airlines Flight 155 from Warsaw Chopin to Tel Aviv Ben Gurion, operated under a wet-lease by Bulgaria’s Electra Airways on an Airbus A320-200, registration LZ-EAH.
Where did the aircraft land?
The aircraft was diverted to Burgas Airport on Bulgaria’s Black Sea coast, where Electra Airways is headquartered. It touched down at 5:12 pm local time on Tuesday, June 30, 2026.
Why did three air forces scramble?
A 7500 squawk obliges air traffic control and militaries to treat the flight as a hijack in progress until confirmed otherwise. Bulgaria, Israel, and Türkiye each launched interceptors per their national procedures after the same signal appeared.
What caused the false alarm?
Bulgaria’s transport ministry said a technical failure of the aircraft’s transponder broadcast the false 7500. An airport official had earlier told reporters the Bulgarian operator attributed it to pilot error.
Bulgaria’s transport ministry said the false 7500 squawk stemmed from a technical transponder failure, not a hijack.
