Investigation Summary
Flight 402 was operating a scheduled weekly service from London to Tel Aviv with multiple stops. After departing Vienna, the aircraft was supposed to follow the Amber 10 airway through Yugoslav and Greek airspace to avoid the hostile territory of the People's Republic of Bulgaria. For reasons that remain disputed, including potential navigational errors caused by thunderstorm activity affecting NDB equipment, the aircraft veered off course and penetrated Bulgarian airspace near the town of Tran. Bulgarian Air Defense scrambled two MiG-15 jets from Dobroslavtsi airport. The fighter pilots claimed they fired warning shots, and that the Constellation initially lowered its gear and flaps as if to land before retracting them and attempting to flee toward the Greek border. Under orders from General Velitchko Georgiev, the fighters engaged the airliner in three distinct phases. The first attack occurred at Flight Level 180, followed by a second attack as the aircraft descended through 8,000 feet. A final attack at 2,000 feet caused the aircraft to break apart in mid-air and crash near the village of Rupite, just 7 kilometers from the Greek border.
Final Conclusions
The investigation concluded the aircraft was destroyed by hits to the wings and rear fuselage, causing an in-flight explosion and fire. While the Bulgarian government initially blamed the crew for the unauthorized entry, they eventually admitted the fighter pilots were too hasty and agreed to pay compensation. The exact reason for the navigational deviation was never definitively proven, though it was established the aircraft had traveled 200km inside Bulgarian territory. In May 1959, the International Court of Justice ruled that it lacked jurisdiction to decide the dispute. A final settlement of $195,000 for the Israeli victims was reached in 1963.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
NDB (Non-Directional Beacon)
The primary navigation system used by the crew; suspected to have been affected by atmospheric interference.
MiG-15 Armament
The fighter jets used large-caliber cannons to strike the right wing and rear fuselage of the airliner.
Interesting Facts
- 01The aircraft was flying at Flight Level 180 (18,000 feet) when it strayed off the Amber 10 airway.
- 02Bulgaria initially refused to allow a six-man Israeli investigative team to participate in the inquiry.
- 03The shoot-down occurred only 7 kilometers from the Bulgarian-Greek border.
- 04A small amount of mail was salvaged from the crash and delivered with a special Hebrew instructional marking.
- 05The Bulgarian government eventually issued a formal apology and paid compensation to the victims' families.
Safety Actions & Advisories
Airway Navigation Upgrade
Investigators recommended the installation of more VOR (VHF Omnidirectional Range) stations along airway Amber 10 to provide more precise navigation than the single station available at the time.
Known Controversies & Unanswered Questions
Cause of Navigational Deviation
Reference ↗Israeli investigators suggested thunderstorms disrupted NDB signals, while Bulgarian authorities and later aviation historians found no factual evidence of such weather in the area at the time.