1996 Charkhi Dadri mid-air collision

On 12 November 1996, Saudia Flight 763, a Boeing 747 en route from Delhi, India, to Dhahran, Saudi Arabia, and Kazakhstan Airlines Flight 1907, an Ilyushin Il-76 en route from Chimkent, Kazakhstan, to Delhi, collided over the city of Charkhi Dadri, around west of Delhi. The crash killed all 349 people on board both planes, making it the world's deadliest mid-air collision and the deadliest aviation accident ever in India. The final report from the investigation found that "[T]he root and approximate cause of the collision" was the failure of the Kazakh crew to maintain the correct altitude. Contributing factors included the poor English language skills in the Kazakh cockpit resulting in inadequate interpretation of directions provided by air traffic control, and three specific incidents of failures in crew resource management (CRM) by the Kazakh crew. The report also suggested technical enhancements (including ACAS and SSR) that would provide assistance in preventing a future crew's mistakes being allowed to go unchecked in real time. Provided by Wikipedia