Which El Al Constellation was shot down over Bulgaria?

El Al Flight 402 was a weekly service from London to Tel Aviv with stopovers in Vienna and Istanbul. On July 27, 1955, it was operated by the Lockheed Constellation registered 4X-AKC, an L-149 version. It took off from Vienna-Schwechat at 02:53 bound for Istanbul. Since the route passed close to the airspace of communist Bulgaria, the crew had instructions to stay on airway Amber 10, over Yugoslav and Greek territory, considered friendly.

The aircraft strayed off that route and crossed Bulgaria's western border. Two Bulgarian MiG-15 fighters intercepted and attacked it, and the Constellation crashed near Petrich. All seven crew members and 51 passengers died.

The event occurred amid heightened tension between the Eastern and Western blocs, and was the deadliest Constellation accident up to that point. It remains the worst for the L-149 version.

The shooting down of a neutral country's airliner by fighters of a Soviet-bloc state became one of the most serious air incidents of the early Cold War years. For civil aviation, it showed how a navigation error near a closely watched border could have fatal consequences, at a time when international airways skirted hostile territories and ground tracking of aircraft was still limited.

The planned route avoided precisely that risk: after Vienna, the aircraft was to continue over Yugoslav and Greek territory to Istanbul and from there on to Lod Airport, today Ben Gurion Airport. For El Al, it meant the loss of one of its Constellations on one of its regular routes to Europe.