El Al Flight 402, a Boeing 707, was on its route from Tel Aviv, Israel, to New York City, USA, when it accidentally entered Bulgarian airspace on July 27, 1955. This event took place during a time of heightened Cold War tensions, where countries were wary of each other's military capabilities and a quick response to perceived threats was common. Bulgarian Soviet MiG-15 fighter jets were dispatched to intercept the aircraft. Following a brief engagement, they opened fire, shooting the airplane down and killing all 58 occupants onboard, including passengers and crew members.

The incident provoked an international outcry as the civilian nature of the aircraft was indisputable, and it raised serious questions regarding the rules of engagement in the airspace prevalent at the time. The Bulgarian government claimed that the airliner had encroached on their territory and did not respond to attempts to make contact. This explanation, however, was met with skepticism internationally, exacerbating existing tensions between the Eastern Bloc and the West. The immediate aftermath saw demands for accountability from the international community, especially as it involved a civilian airline.

Furthermore, this event pushed discussions related to international aviation laws into the forefront. It highlighted the dangers faced by commercial airlines operating near military borderlines and contributed to the future establishment of clearer rules and communication protocols regarding airspace violations. The tragedy impacted air travel safety standards significantly, urging nations to enhance their air defense protocols while ensuring the protection of civilian flights.