Saudi Arabian Airlines Flight 763 and Kazakhstan Airlines Flight 1907, Delhi (1996)

These two flights collided in mid-air seconds after Flight 763 took off. The control tower had advised the Kazakh aircraft to descend to 15,000 ft on the same path that the Saudi plane was coming in on, albeit in the opposite direction and at 14,000 ft. However, Flight 1907 had already descended to 14,500ft and was losing further altitude. Before air traffic control could mend the situation, the damage had been done.

All 312 on board Flight 763 and the 37 on Flight 1907 died in this tragedy, taking the death toll to 349. After investigations, the Kazakh pilot was found guilty, since he failed to follow instructions from the flight tower and violated one of the principal tenets of modern aviation: always stick to the assigned flight level!